{"title":"Geotextile Water Permeability Tester","description":"\u003ch2\u003e\u003cspan\u003eGeotextile Permeability Testers | ISO 11058 \u0026amp; ASTM D4491 Cross-Plane Flow Testing\u003c\/span\u003e\u003c\/h2\u003e\n\u003cp\u003e\u003cspan\u003eA geotextile permeability tester determines how easily water flows through the thickness of a fabric. This characteristic is essential for evaluating whether a filter provides adequate drainage or becomes clogged. ISO 11058 specifies the measurement of water permeability perpendicular to the fabric plane under zero pressure, with flow velocity reported at a 50 mm hydraulic head. ASTM D4491 evaluates the same property as permittivity under uncompressed conditions.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eQualitest offers ten geotextile permeability tester configurations, ranging from manual bench-top instruments to fully automated systems featuring de-aired, temperature-controlled water. Manufacturers use these instruments for production lot approval, while hydraulic engineers assess filter compatibility with the soil being retained. The range also includes a pressure-operated model designed to measure barrier membranes.\u003c\/span\u003e\u003c\/p\u003e\n\u003ch2\u003e\u003cspan\u003eApplications\u003c\/span\u003e\u003c\/h2\u003e\n\u003cp\u003e\u003cspan\u003eCross-plane permeability testing is essential for filtration and drainage evaluations in civil engineering projects and geosynthetic manufacturing.\u003c\/span\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eGeotextile Manufacturing\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Confirms that woven and nonwoven filter fabrics consistently meet the water flow capacity specified in product data sheets across successive production lots.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eLandfill and Containment\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Evaluates filter geotextile performance above leachate collection layers and beneath drainage systems installed in landfill caps.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eEmbankment Dams and Levees\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Verifies that filter fabrics discharge seepage faster than water enters from the surrounding soil, preventing pressure buildup behind the fabric.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eCanal and Reservoir Lining\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Assesses fabrics installed beneath lining systems to prevent trapped seepage from lifting or displacing the lining.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eHighway and Railway Drainage\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Checks the performance of separation and filtration fabrics used in edge drains, drainage blankets, and subgrade applications.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eCoastal and Erosion Control\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Measures water flow through fabrics placed beneath riprap, gabions, and revetments, where inadequate filtration can result in soil loss.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eBarrier Liner Qualification\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Determines the permeability coefficient of geomembranes and waterproofing sheets under applied pressure.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eAcceptance and Third-Party Laboratories\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Supports shipment acceptance inspections of commercial geotextile deliveries before materials are released for installation.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003e\u003cspan\u003eGeotextile Permeability Tester Range\u003c\/span\u003e\u003c\/h2\u003e\n\u003cp\u003e\u003cspan\u003eQualitest offers ten models to accommodate everything from occasional bench-top measurements to high-throughput, fully automated laboratory testing. Nine models force water through the specimen using a hydraulic head, while the tenth uses pump-generated pressure for testing barrier membranes.\u003c\/span\u003e\u003c\/p\u003e\n\u003ctable class=\"table table-style-align-center\" align=\"center\" border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eModel\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cstrong\u003eTest Principle\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cstrong\u003eControl and Automation\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cstrong\u003eDescription\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eQualiGTX™ GPT MN\u003c\/td\u003e\n\u003ctd\u003eConstant head, 250 mm maximum\u003c\/td\u003e\n\u003ctd\u003eManual valve control, timer to 0.01 s\u003c\/td\u003e\n\u003ctd\u003eBenchtop unit with a ø50 mm clamp, 1000 mL graduated cylinder, and integrated 0 to 50 °C thermometer. Accepts specimens up to 20 mm thick. At 36 kg it suits laboratories running permeability as an occasional confirmation test.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eQualiGTX™  GPT E\u003c\/td\u003e\n\u003ctd\u003eHead driven, ASTM D4491 configuration\u003c\/td\u003e\n\u003ctd\u003eTouchscreen, automatic timing\u003c\/td\u003e\n\u003ctd\u003eEntry-level cabinet configured for permittivity testing, with dissolved oxygen measurement fitted. The most direct route to a standards-referenced result for routine quality control.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eQualiGTX™ GPT GS\u003c\/td\u003e\n\u003ctd\u003eHead driven, ISO 11058 configuration\u003c\/td\u003e\n\u003ctd\u003eTouchscreen, automatic timing\u003c\/td\u003e\n\u003ctd\u003eShares the QualiGTX™ GPT E chassis, configured for velocity index testing with full dissolved oxygen specification. Choose it where reporting follows the ISO route rather than ASTM.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eQualiGTX™ GPT V\u003c\/td\u003e\n\u003ctd\u003eHead driven, fixed 20 cm² test area\u003c\/td\u003e\n\u003ctd\u003eTouchscreen, automatic timing\u003c\/td\u003e\n\u003ctd\u003eFloor-standing analyzer for water resources work, with a machined aluminum alloy clamp that seals the specimen perimeter against edge leakage. Built for dam, levee, and canal filter verification.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eQualiGTX™ GPT GW\u003c\/td\u003e\n\u003ctd\u003eHead driven, ø80 mm test area\u003c\/td\u003e\n\u003ctd\u003eTouchscreen, automatic timing\u003c\/td\u003e\n\u003ctd\u003eFloor-standing system with heated and cooled water held at a set point, plus a custom-configured source tank. The largest test area in the range at roughly 50 cm², which tightens repeatability on nonwovens that vary in density across a roll.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eQualiGTX™ GPT T\u003c\/td\u003e\n\u003ctd\u003eHead driven, thermostatic bath\u003c\/td\u003e\n\u003ctd\u003eTouchscreen, temperature and DO control\u003c\/td\u003e\n\u003ctd\u003eHolds test water between 10 °C and 60 °C with dissolved oxygen control. Suits laboratories that study how flow capacity shifts with temperature rather than correcting for it after the run.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eQualiGTX™ GPT M\u003c\/td\u003e\n\u003ctd\u003eHead driven, motorized water level\u003c\/td\u003e\n\u003ctd\u003eTouchscreen, powered head adjustment\u003c\/td\u003e\n\u003ctd\u003eSteps the head through several settings without a manual reset at each point. Multiple head readings show whether flow has left the laminar regime, which decides whether the reported coefficient is valid.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eQualiGTX™ GPT A\u003c\/td\u003e\n\u003ctd\u003eHead driven, automated head sequence\u003c\/td\u003e\n\u003ctd\u003eTouchscreen, automated positioning and timing\u003c\/td\u003e\n\u003ctd\u003eRuns the full sequence with minimal operator input, with compressor cooling on the water circuit. Built for laboratories processing specimens in volume, where setup minutes accumulate across a shift.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eQualiGTX™ GPT D\u003c\/td\u003e\n\u003ctd\u003eHead driven, de-aired water supply\u003c\/td\u003e\n\u003ctd\u003eTouchscreen, de-aeration and DO control\u003c\/td\u003e\n\u003ctd\u003eTop of the range, combining de-aired water, dissolved oxygen control, and temperature regulation. Removing dissolved air stops bubbles lodging in the pore structure and drifting readings downward through a run.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eQualiGTX™ GPT GM 100\u003c\/td\u003e\n\u003ctd\u003eApplied pressure, 0 to 1 MPa\u003c\/td\u003e\n\u003ctd\u003e10-inch touchscreen, automatic timing\u003c\/td\u003e\n\u003ctd\u003ePressure driven rather than head driven, measuring the permeability coefficient of barrier membranes across three specimens at once. Built for liner qualification, where the flow being measured sits close to zero.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch2\u003e\u003cspan\u003eHow to Choose the Right Geotextile Permeability Tester\u003c\/span\u003e\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eFor occasional confirmation testing on a bench\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Select the GPT MN, which offers a limited calibration scope and requires a bench area of 500 × 550 mm.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eFor standards-based testing at an economical entry cost\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Choose the QualiGTX™ GPT E for ASTM D4491 permittivity measurements or the GPT GS for the ISO 11058 velocity index.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eFor dam, levee, and canal filter verification\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Choose the GPT V, designed around the fixed 20 cm² test area commonly used in water resources testing.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eFor improved repeatability when testing non-uniform nonwoven fabrics\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Select the GPT GW, featuring a 50 cm² test area that evaluates a larger portion of the fabric structure in each specimen.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eFor applications requiring controlled test temperatures rather than temperature corrections\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Choose the GPT GW or QualiGTX™ GPT T, both of which regulate water temperature from 10 °C to 60 °C.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eFor confirming laminar flow conditions\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Select the GPT M, which features a motorized head and collects measurements at multiple head points during a single test.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eFor high specimen throughput\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Choose the QualiGTX™ GPT A for automated test sequencing, or the GPT D when de-aired water is required to maintain stability during extended testing.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eFor geomembranes and waterproofing sheets\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Select the QualiGTX™ GPT GM 100, the only pressure-driven instrument in the range.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003e\u003cspan\u003eWhy Choose Qualitest for Your Geotextile Permeability Tester\u003c\/span\u003e\u003c\/h2\u003e\n\u003cp\u003e\u003cspan\u003eQualitest North America provides testing and measurement equipment for laboratories, quality control departments, and manufacturers, supported by responsive technical assistance and calibration services. Our geotextile permeability tester range is designed to deliver dependable results in accordance with applicable testing standards, allowing customers to source their equipment and technical support through one trusted supplier.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eOur specialists help identify the appropriate instrument configuration based on your specimen types, applicable standards, and testing volume. From initial equipment selection and installation to ongoing technical assistance, Qualitest supports your testing requirements at every stage.\u003c\/span\u003e\u003c\/p\u003e\n\u003ch2\u003e\u003cspan\u003eRequest a Quote\u003c\/span\u003e\u003c\/h2\u003e\n\u003cp\u003e\u003cspan\u003eShare details about the fabrics you test, the applicable testing standard, and your testing frequency so our team can recommend a suitable geotextile permeability tester.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003e\u003ca href=\"https:\/\/qualitest.us\/pages\/contact\"\u003eContact the Qualitest team\u003c\/a\u003e\u003ca href=\"https:\/\/www.worldoftest.com\/contact\/\"\u003e\u003c\/a\u003e\u003c\/span\u003e\u003cspan\u003e to request pricing information and current lead times.\u003c\/span\u003e\u003c\/p\u003e","products":[{"product_id":"de-aired-geotextile-permeability-tester","title":"De-Aired Geotextile Permeability Tester","description":"\u003cdiv\u003e\n\u003ch2\u003eDe-Aired Geotextile Permeability Tester – QualiGTX™ GPT D\u003c\/h2\u003e\n\u003cp\u003eThe QualiGTX™ GPT D de-aired geotextile permeability tester evaluates the vertical water flow properties of geotextiles and related materials under zero-load conditions. Developed by Qualitest North America, this system features a de-aired, temperature-regulated water supply that minimizes measurement errors caused by entrained air in conventional permeability testing. An industrial touchscreen computer automates specimen clamping, hydraulic head positioning, test timing, and calculations. The system directly determines the vertical permeability coefficient, eliminating manual stopwatch operation and calculations.\u003c\/p\u003e\n\u003cp\u003eDesigned for civil engineering laboratories, geosynthetic manufacturers, and infrastructure quality-control facilities, the QualiGTX™ GPT D helps verify filter fabric performance before installation in subgrades, embankments, and drainage structures. It accommodates 50 mm specimens, applies a user-defined head difference of up to 250 mm, and measures the water volume passing through the specimen over a specified period. An integrated dissolved oxygen analyzer verifies that the test water satisfies the deaeration requirement before testing begins. Completed results can be generated as reports and uploaded or printed directly from the control station.\u003c\/p\u003e\n\u003cp\u003eThe instrument features interchangeable water-supply configurations, allowing multiple vertical permeability testing protocols to be performed without changing hardware. Operators select the appropriate configuration through the touchscreen, and the system automatically directs water through the corresponding supply unit. Its 50 L stainless steel thermostatic tank uses PID temperature control to maintain water temperature within ±0.5 °C. This stability is essential because temperature affects water viscosity and consequently influences measured flow rates. These controlled conditions support consistent and repeatable results across different operators, work shifts, and seasonal conditions.\u003c\/p\u003e\n\u003ch2\u003eDe-Aired Geotextile Permeability Tester – QualiGTX™ GPT D Applications\u003c\/h2\u003e\n\u003cp\u003eThe QualiGTX™ GPT D is designed for testing geosynthetic filtration and drainage materials used in civil engineering, hydraulic infrastructure, and transportation projects.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eGeotextile Manufacturing Quality Control: Verifies production batches of woven and nonwoven geotextiles against specified permittivity and water flow-rate values before shipment.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eHighway and Roadway Construction: Evaluates separation and filtration fabrics installed between subgrade soils and aggregate base layers for construction acceptance.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eDam, Levee, and Canal Engineering: Assesses filter materials designed to allow seepage water to pass while preventing fine soil particles from escaping through the fabric.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eRailway Subgrade Engineering: Qualifies geotextiles used to minimize mud pumping and maintain effective drainage beneath railway ballast.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003ePort, Coastal, and Reclamation Works: Tests geotextiles used in revetments, breakwater cores, and dredged-material containment applications subject to continuous hydraulic loading.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eLandfill and Environmental Containment: Checks the performance of leachate collection and drainage materials positioned above liner systems.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eErosion Control and Land Drainage: Evaluates filtration fabrics used in French drains, trench drainage systems, and slope protection installations.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eThird-Party and Certification Laboratories: Provides independent verification of supplier test data for project acceptance and tender documentation.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eMaterials Research and Product Development: Compares fiber compositions, pore structures, and manufacturing methods based on measured cross-plane water flow performance.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eDe-Aired Geotextile Permeability Tester – QualiGTX™ GPT D Key Features\u003c\/h2\u003e\n\u003cp\u003eThe QualiGTX™ GPT D integrates water conditioning, automated specimen handling, and automatic result processing into a single floor-standing testing system.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eIntegrated De-Aeration and Thermostatic Water System: Conditions test water within an integrated circuit, eliminating the need for separate vacuum deaeration equipment and additional transfer procedures that could introduce air back into the water.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eDissolved Oxygen Measurement System: Displays oxygen concentration in mg\/L, percentage saturation, and partial pressure to document compliance with the required water deaeration conditions.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eIndustrial Touchscreen Computer Control: Provides guided test setup, automated run recording, and parameter storage to maintain consistent operating procedures between technicians.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eAutomatic Specimen Clamping: Positions and seals specimens automatically without manual tightening, reducing edge leakage and variations caused by operator handling.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eAutomatic Head Positioning: Moves the testing assembly to the specified hydraulic head difference and establishes the required position without manual leveling or shimming.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eConstant Water Level Device: Maintains a stable driving head throughout the test to prevent changes in the hydraulic gradient.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eTwo-Unit Lateral Supply Stabilization: Quickly establishes the target hydraulic head and reduces surface fluctuations, minimizing the stabilization time required before measurements begin.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eSwitchable Supply Configurations: Allows operators to select different testing protocols through the control panel, enabling one instrument to perform the work of multiple dedicated permeameters.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eAutomatic Flow Collection and Timing: Records collected water volume against elapsed time with 1 s resolution, removing timing inconsistencies associated with manual stopwatch operation.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eAutomatic Permeability Calculation and Reporting: Processes measured flow data to determine the vertical permeability coefficient and prepares reports for direct uploading or printing.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003e304 Stainless Steel Wetted Parts: Uses corrosion-resistant 304 stainless steel for the specimen clamp and water tank, supporting long-term durability under continuous water contact.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eElectrostatic Powder-Coated Working Vessel: Provides a durable protective coating over the stainless steel surface for reliable operation in humid laboratory environments.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eCorrosion-Resistant Silicone Sealing Rings: Maintain an effective specimen seal through repeated clamping cycles while resisting hardening and leakage.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eAdjustable PID Control with Auto-Tuning: Enables users to adjust the temperature control loop to suit laboratory operating conditions rather than relying exclusively on fixed factory settings.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eTemperature Deviation Correction: Allows temperature readings to be adjusted in 0.1 °C increments to support accurate viscosity-related corrections.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eInternal and External Circulation Modes: Supports internal circulation during testing and external circulation for transferring conditioned liquid to other vessels for heating or cooling, expanding the system's laboratory applications.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eOutdoor Condenser Unit Cooling: Transfers compressor heat outside the laboratory, helping reduce indoor heat accumulation and energy consumption during extended temperature-holding periods.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eTheory and Method\u003c\/h2\u003e\n\u003cp\u003eGeotextile permeability testing is based on Darcy's law, which describes the relationship between fluid flow through a porous material and the hydraulic gradient across it. The QualiGTX™ GPT D maintains a constant hydraulic head difference across a secured specimen and measures the volume of water passing through a defined area during a controlled time interval. Dividing the volumetric flow rate by the specimen area and hydraulic head difference determines permittivity, representing water flow per unit area and unit head. Multiplying the permittivity by the specimen thickness provides the vertical permeability coefficient used in drainage and filtration engineering design.\u003c\/p\u003e\n\u003cp\u003eDissolved air is a significant potential source of measurement error during permeability testing. Tap water contains dissolved oxygen and nitrogen, which can separate from the water when pressure conditions change, forming microscopic bubbles within the fine pore structure of nonwoven geotextiles. These bubbles obstruct water flow paths, reduce the measured flow rate, and produce permeability results lower than the material's actual performance. To minimize this problem, the QualiGTX™ GPT D removes dissolved gases from the test water before measurement and verifies the deaeration level using its integrated dissolved oxygen analyzer.\u003c\/p\u003e\n\u003cp\u003eWater viscosity decreases as temperature increases, allowing a geotextile specimen to pass more water at 30 °C than at 15 °C under otherwise identical conditions. Standard testing methods account for this temperature-related variation by correcting measurements to a reference temperature. However, accurate correction requires the water temperature to remain known and stable throughout testing. The QualiGTX™ GPT D uses a PID-controlled thermostatic tank and circulating water system to maintain temperature within ±0.5 °C while providing temperature measurement correction to ±0.1 °C. Its two-unit lateral water supply rapidly stabilizes the hydraulic head and minimizes water surface fluctuations, maintaining a consistent driving gradient throughout the measurement process.\u003c\/p\u003e\n\u003ch2\u003eDe-Aired Geotextile Permeability Tester - QualiGTX™ GPT D Technical Specifications\u003c\/h2\u003e\n\u003cdiv\u003e\n\u003ctable class=\"table table-style-align-center\" align=\"center\" border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"594\"\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eParameter\u003c\/th\u003e\n\u003cth\u003eSpecification\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eMaximum Head Differential\u003c\/td\u003e\n\u003ctd\u003e250 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSpecimen Clamp Inner Diameter\u003c\/td\u003e\n\u003ctd\u003eØ50 ± 0.5 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMaximum Specimen Thickness\u003c\/td\u003e\n\u003ctd\u003e20 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTiming Range\u003c\/td\u003e\n\u003ctd\u003e0 to 9,999 s\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTemperature Measurement Range\u003c\/td\u003e\n\u003ctd\u003e0 °C to 110 °C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTemperature Control Range\u003c\/td\u003e\n\u003ctd\u003e5 °C to 100 °C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTemperature Accuracy\u003c\/td\u003e\n\u003ctd\u003e±0.5 °C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTemperature Correction Accuracy\u003c\/td\u003e\n\u003ctd\u003e±0.1 °C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDissolved Oxygen Range\u003c\/td\u003e\n\u003ctd\u003e0 to 20 mg\/L; 0 to 200 %; 0 to 400 hPa\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDissolved Oxygen Accuracy\u003c\/td\u003e\n\u003ctd\u003e±1.5 % FS\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDissolved Oxygen Repeatability\u003c\/td\u003e\n\u003ctd\u003e±0.5 % FS\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDissolved Oxygen Resolution\u003c\/td\u003e\n\u003ctd\u003e0.01 mg\/L; 0.1 %; 1 hPa\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWater Supply Tank Capacity\u003c\/td\u003e\n\u003ctd\u003e50 L\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCooling Capacity\u003c\/td\u003e\n\u003ctd\u003e13,000 W\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCirculation Modes\u003c\/td\u003e\n\u003ctd\u003eInternal and external\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTemperature Control Modes\u003c\/td\u003e\n\u003ctd\u003eCooling and heating\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCooling Method\u003c\/td\u003e\n\u003ctd\u003eOutdoor condenser unit\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCompressor Power\u003c\/td\u003e\n\u003ctd\u003e1.5 hp (approx. 1.1 kW)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInternal Circulation Pump Power\u003c\/td\u003e\n\u003ctd\u003e100 W\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eExternal Circulation Pump\u003c\/td\u003e\n\u003ctd\u003e100 W, adjustable flow\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCirculation Pump Flow Rate\u003c\/td\u003e\n\u003ctd\u003e45 L\/min\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTemperature Control\u003c\/td\u003e\n\u003ctd\u003ePID with auto-tuning\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eHeating Time\u003c\/td\u003e\n\u003ctd\u003eRoom temperature to boiling, approx. 30 min\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCooling Time\u003c\/td\u003e\n\u003ctd\u003eBoiling to 20 °C, approx. 90 min\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWater Conditioning System Power Supply\u003c\/td\u003e\n\u003ctd\u003e380 V, 50 Hz, 12 kW\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTest Operation Power\u003c\/td\u003e\n\u003ctd\u003e1 kW\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDimensions (W × D × H)\u003c\/td\u003e\n\u003ctd\u003e1,380 × 780 × 1,870 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e160 kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e","brand":"Qualitest USA LC","offers":[{"title":"Default Title","offer_id":53459725287735,"sku":null,"price":100.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0786\/1859\/1543\/files\/de-aired-geotextile-permeability.webp?v=1793363170"},{"product_id":"temperature-controlled-geotextile-permeability-tester","title":"Temperature-Controlled Geotextile Permeability Tester","description":"\u003cdiv\u003e\n\u003ch2\u003eTemperature-Controlled Geotextile Permeability Tester – QualiGTX™ GPT T\u003c\/h2\u003e\n\u003cp\u003eThe QualiGTX™ GPT T geotextile permeability tester determines the vertical water flow rate through geotextiles and related materials under no-load conditions, with test water maintained between 10 °C and 60 °C. Its thermostatically regulated water circuit addresses temperature-related changes in water viscosity, reducing test variability that cannot be eliminated through specimen replication alone. The computer-controlled system automatically positions the water head, measures test duration, and calculates the vertical permeability coefficient. Test reports are generated in a format suitable for uploading or printing.\u003c\/p\u003e\n\u003cp\u003eDesigned for geosynthetics manufacturers, civil engineering laboratories, and construction quality control departments, the QualiGTX™ GPT T supports the evaluation of filtration and drainage fabrics before installation. Its 304 stainless steel specimen clamp accommodates samples measuring 50 mm in diameter and up to 20 mm thick. Operators can select any head height within a maximum differential of 250 mm. The instrument automatically identifies the zero water level and maintains the required level through a metered water supply system rather than an overflow weir. A dissolved oxygen analyzer also verifies water quality before testing.\u003c\/p\u003e\n\u003cp\u003eThe automated 70 mm head differential sequence completes measurements across the 0.8 to 0.2 head range without manual intervention, with timing accuracy of 0.1 s. A 36 L stainless steel water tank, PID temperature control system, and 15 L\/min circulation pump maintain stable test conditions. Temperature deviation is corrected to ±0.1 °C, providing the measurement basis for viscosity correction in the final results. With an overall cabinet width of 1,150 mm, the tester fits standard laboratory floor layouts.\u003c\/p\u003e\n\u003ch2\u003eTemperature-Controlled Geotextile Permeability Tester – QualiGTX™ GPT T Applications\u003c\/h2\u003e\n\u003cp\u003eThe QualiGTX™ GPT T is suitable for laboratories that require dependable cross-plane water flow measurements across different seasons, project locations, and independent verification procedures.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eNonwoven and Woven Geotextile Production: Performs routine production lot inspections to verify declared permittivity and water flow-rate values before materials leave the manufacturing facility.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eRoadway and Highway Subgrade Work: Evaluates separation and filtration geotextiles installed between soft subgrade soils and granular base materials.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003ePort, Harbor, and Waterway Construction: Assesses geotextiles used in revetments, quay backfill, and dredged material containment under sustained hydraulic loading.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eCanal, Reservoir, and Embankment Drainage: Verifies that filtration layers allow seepage water to pass while retaining fine soil particles.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eRetaining Wall and Slope Drainage Systems: Measures the flow capacity of geotextiles surrounding drainage aggregate and used in blanket drain installations.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eLandfill Leachate Collection Layers: Checks whether protective and drainage geotextiles installed above liners satisfy specified design flow requirements.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eAgricultural and Land Drainage: Evaluates wrapping materials used with perforated drainage pipes and trench drainage systems.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eIndependent Testing and Certification Houses: Conducts verification and arbitration testing to validate supplier results for tender submissions and material acceptance documentation.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eFiber and Fabric Development Programs: Examines relationships between pore structure, basis weight, and needling processes through measured hydraulic conductivity results.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eTemperature-Controlled Geotextile Permeability Tester – QualiGTX™ GPT T Key Features\u003c\/h2\u003e\n\u003cp\u003eThe QualiGTX™ GPT T combines thermostatically regulated water circulation, automatic head positioning, and computerized result processing to deliver consistent geotextile vertical permeability measurements.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003e10 °C to 60 °C Thermostatic Water Circuit: Heats or cools test water to the selected temperature and maintains it within ±0.5 °C, minimizing seasonal temperature variations during comparative testing.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eAutomated 70 mm Head Differential Sequence: Automatically performs the test across the 0.8 to 0.2 head range, ensuring consistent procedures between different operators.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eAutomatic Zero Water Level Positioning: Identifies the reference water level without manual leveling or shimming, reducing specimen setup time.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eFreely Programmable Head Height: Allows operators to select any water level within the 250 mm differential range according to the applicable test procedure or specimen requirements.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eMetered Water Supply Flow System: Replenishes water passing through the specimen at a controlled rate to maintain a stable driving head throughout the measurement.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eDissolved Oxygen Measurement System: Measures and displays dissolved oxygen in mg\/L, percentage saturation, and partial pressure, allowing water quality to be verified and recorded.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eAutomatic Volume Collection and Timing: Measures collected water volume alongside elapsed time with 0.1 s resolution, eliminating reliance on manual stopwatch readings.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eAutomatic Permeability Calculation and Reporting: Processes measured flow data to determine the vertical permeability coefficient and generates reports for uploading or printing.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eSelectable Test Configurations: Supports multiple vertical permeability testing protocols through the control software, allowing different reporting formats to be handled by one instrument.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eComputer Control with Simple Operation: Provides guided test setup and parameter storage through the control computer, simplifying operation and reducing training requirements for laboratory personnel.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eTemperature Deviation Correction: Corrects measured temperature deviation to an accuracy of 0.1 °C, providing a reliable basis for water viscosity adjustments.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eUser-Adjustable PID with Auto-Tuning: Allows the thermal control loop to be adjusted and automatically tuned to suit laboratory ambient conditions rather than relying exclusively on fixed factory settings.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003e304 Stainless Steel Water Tank and Clamp: Provides corrosion resistance during continuous water exposure and repeated specimen clamping operations.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003e304 Stainless Steel Water Line Fittings: Maintain a corrosion-resistant wetted flow path, preventing rust contamination that could affect specimens or distort flow measurements.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eElectrostatic Powder-Coated Working Vessel: Provides an additional protective surface finish over stainless steel for reliable operation in humid laboratory environments.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eTheory and Method\u003c\/h2\u003e\n\u003cp\u003eVertical permeability testing evaluates cross-plane water movement by measuring the volume of water passing through a unit area of geotextile under a unit hydraulic head over a specified period. Darcy's law describes this relationship when the water flow remains laminar. The QualiGTX™ GPT T applies a defined head difference across the clamped specimen, collects the water passing through the material, and calculates the ratio of collected volume to specimen area, hydraulic head, and elapsed time. This value represents permittivity. Multiplying permittivity by the specimen thickness produces the permeability coefficient used in drainage design calculations.\u003c\/p\u003e\n\u003cp\u003eWater temperature is a major factor affecting vertical permeability measurements. At 10 °C, water is approximately 1.6 times as viscous as it is at 30 °C. Consequently, an identical geotextile specimen allows noticeably less water to pass through it at the lower temperature. Standard test methods account for this difference by converting measured results to a reference temperature using a viscosity ratio. The accuracy of this correction depends directly on the reliability of the temperature measurement. The QualiGTX™ GPT T maintains bath temperature within ±0.5 °C and corrects temperature deviation to ±0.1 °C.\u003c\/p\u003e\n\u003cp\u003eDissolved gases represent another potential source of measurement error. Air dissolved in water can form microscopic bubbles within the pore structure of nonwoven geotextiles. These bubbles obstruct flow channels and reduce the measured water flow rate. To address this factor, the QualiGTX™ GPT T includes a dissolved oxygen analyzer with a measurement range of 0 to 20 mg\/L. Operators can verify water quality before testing and include the readings in the test report. Consistent hydraulic head is equally important for reliable results. The instrument uses a metered water supply to replace the water passing through the specimen, maintaining the selected hydraulic gradient throughout the measurement.\u003c\/p\u003e\n\u003ch2\u003eTemperature-Controlled Geotextile Permeability Tester - QualiGTX™ GPT T Technical Specifications\u003c\/h2\u003e\n\u003ctable class=\"table table-style-align-center\" align=\"center\" border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"498\"\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eParameter\u003c\/th\u003e\n\u003cth\u003eSpecification\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eMaximum Head Differential\u003c\/td\u003e\n\u003ctd\u003e250 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSpecimen Clamp Inner Diameter\u003c\/td\u003e\n\u003ctd\u003eØ50 ± 0.5 mm (304 stainless steel)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMaximum Specimen Thickness\u003c\/td\u003e\n\u003ctd\u003e20 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTiming Range\u003c\/td\u003e\n\u003ctd\u003e0 to 9,999 s\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTiming Accuracy\u003c\/td\u003e\n\u003ctd\u003e0.1 s\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTemperature Measurement Range\u003c\/td\u003e\n\u003ctd\u003e0 °C to 110 °C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTemperature Control Range\u003c\/td\u003e\n\u003ctd\u003e10 °C to 60 °C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTemperature Control Accuracy\u003c\/td\u003e\n\u003ctd\u003e±0.5 °C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eThermometer Accuracy\u003c\/td\u003e\n\u003ctd\u003e0.1 °C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTemperature Correction Accuracy\u003c\/td\u003e\n\u003ctd\u003e±0.1 °C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDissolved Oxygen Range\u003c\/td\u003e\n\u003ctd\u003e0 to 20 mg\/L; 0 to 200 %; 0 to 400 hPa\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDissolved Oxygen Accuracy\u003c\/td\u003e\n\u003ctd\u003e±1.5 % FS\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDissolved Oxygen Repeatability\u003c\/td\u003e\n\u003ctd\u003e±0.5 % FS\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDissolved Oxygen Resolution\u003c\/td\u003e\n\u003ctd\u003e0.01 mg\/L; 0.1 %; 1 hPa\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWater Supply Tank Capacity\u003c\/td\u003e\n\u003ctd\u003e36 L\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTemperature Control Modes\u003c\/td\u003e\n\u003ctd\u003eCooling and heating\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCooling Method\u003c\/td\u003e\n\u003ctd\u003eCompressor unit\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTemperature Control\u003c\/td\u003e\n\u003ctd\u003ePID with auto-tuning\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCompressor Power\u003c\/td\u003e\n\u003ctd\u003e550 W\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInternal Circulation Pump Power\u003c\/td\u003e\n\u003ctd\u003e100 W\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCirculation Pump Flow Rate\u003c\/td\u003e\n\u003ctd\u003e15 L\/min\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTotal Power\u003c\/td\u003e\n\u003ctd\u003e1 kW\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDimensions (W × D × H)\u003c\/td\u003e\n\u003ctd\u003e1,150 × 670 × 1,580 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e180 kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e","brand":"Qualitest USA LC","offers":[{"title":"Default Title","offer_id":53459726336311,"sku":null,"price":100.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0786\/1859\/1543\/files\/temperature-controlled-geotextil.webp?v=1793363391"},{"product_id":"automatic-geotextile-permeability-tester","title":"Automatic Geotextile Permeability Tester","description":"\u003ch2\u003e\u003cspan\u003eAutomatic Geotextile Permeability Tester – QualiGTX™ GPT A\u003c\/span\u003e\u003c\/h2\u003e\n\u003cp\u003e\u003cspan\u003eThe QualiGTX™ GPT A Automatic Geotextile Permeability Tester is designed to perform vertical water permeability testing on geotextiles and related materials with minimal operator involvement. Configured by Qualitest North America for high-volume laboratory environments, this automated geotextile permeameter reduces the time spent on water-level adjustment, timing, and calculations. Its computer-controlled system positions the water level, manages the testing sequence, measures water flow, and calculates the vertical permeability coefficient. Test reports can be uploaded or printed directly from the control screen.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eGeosynthetics manufacturers, hydraulic engineering laboratories, and infrastructure quality control departments use the QualiGTX™ GPT A to evaluate filter and drainage fabrics before project application. Its 304 stainless steel specimen clamp accommodates samples measuring up to 50 mm in diameter and 20 mm in thickness, while the operator can configure a head differential of up to 250 mm. Flow measurement uses 0.1-second timing resolution, providing precise readings for high-permittivity fabrics with shorter water collection intervals. A dissolved oxygen analyzer also checks the test water before measurement begins.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThe automated 70 mm head differential test follows the 0.8 to 0.2 range, minimizing operator-dependent variations and improving consistency between technicians. A 36 L stainless steel water tank features compressor cooling and PID temperature control, maintaining water temperatures between 10 °C and 60 °C. All water-contact components, including the tank, specimen clamp, and water line fittings, are constructed from 304 stainless steel. The instrument requires a floor area of 1,150 × 670 mm and has a total weight of 180 kg.\u003c\/span\u003e\u003c\/p\u003e\n\u003ch2\u003e\u003cspan\u003eAutomatic Geotextile Permeability Tester – QualiGTX™ GPT A Applications\u003c\/span\u003e\u003c\/h2\u003e\n\u003cp\u003e\u003cspan\u003eThe QualiGTX™ GPT A is suitable for laboratories involved in hydraulic, railway, and marine infrastructure projects, where filter and drainage fabric performance requires consistent batch-by-batch verification.\u003c\/span\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eDam, Reservoir, and Canal Engineering\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Evaluates the flow capacity of filter and drainage fabrics installed against earth structures exposed to continuous seepage.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eRailway Subgrade and Trackbed Materials\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Qualifies geotextiles used to separate ballast from subgrade materials and facilitate water drainage away from the formation.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eMarine and Port Construction\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Verifies geotextile performance in breakwater cores, quay wall backfill, and reclamation containment bunds.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eFlood Defense and Levee Works\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Measures cross-plane water flow through filter layers installed behind revetments and within toe drainage systems.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eGeotextile Production Line Testing\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Performs batch release inspections against published permittivity values before finished rolls are dispatched.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eHighway and Airfield Drainage\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Assesses edge drain wrapping and separation fabrics installed beneath pavement structures.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eMining and Tailings Management\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Tests drainage geotextiles used in heap leach pads and tailings dam underdrain systems.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eAccredited and Third-Party Laboratories\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Supports high-throughput verification testing, where consistency between operators is as important as measurement accuracy.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eProduct Development and Failure Investigation\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Compares pore structure and manufacturing variables with measured cross-plane water flow to support product evaluation and failure analysis.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003e\u003cspan\u003eAutomatic Geotextile Permeability Tester – QualiGTX™ GPT A Key Features\u003c\/span\u003e\u003c\/h2\u003e\n\u003cp\u003e\u003cspan\u003eThe QualiGTX™ GPT A automates three time-consuming stages of vertical geotextile permeability testing: water-level adjustment, measurement timing, and coefficient calculation.\u003c\/span\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eAutomated 70 mm Head Differential Test\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Automatically completes the test sequence across the 0.8 to 0.2 range, allowing technicians to prepare subsequent specimens while testing continues.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eSelf-Locating Zero Water Level\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Automatically identifies the zero water-level reference without manual shimming or visual level estimation, maintaining consistent setup between specimens.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eProgrammable Head Height\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Allows users to configure any water level within the 250 mm differential range according to the applicable testing procedure or specimen characteristics.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003e0.1 s Timing Resolution\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Provides accurate timing for short water collection intervals, particularly when testing free-draining fabrics where manual stopwatch measurements can introduce significant errors.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eControlled Water Supply Metering\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Regulates replacement water delivery at a measured rate to maintain the required hydraulic head throughout the collection period.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eDissolved Oxygen Analyzer\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Measures dissolved oxygen in mg\/L, percentage saturation, and partial pressure, documenting water conditions before testing begins.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003e10 °C to 60 °C Thermostatic Tank\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Provides controlled heating and compressor cooling while maintaining water temperature within ±0.5 °C for comparable results across seasonal testing conditions.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eAutomatic Volume and Time Capture\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Records collected water volume alongside elapsed time, eliminating manual readings and reducing data transcription errors.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eAutomatic Coefficient Calculation and Reporting\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Processes measured flow data to determine the vertical permeability coefficient and generates reports for direct uploading or printing.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eSelectable Test Configurations\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Offers multiple vertical permeability testing protocols through the software, allowing one instrument to accommodate different reporting requirements.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eComputer Control with a Short Learning Curve\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Guides technicians through the testing process and retains configuration parameters between runs, simplifying operation and staff handovers.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eTemperature Deviation Correction to 0.1 °C\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Adjusts measured temperature values to support viscosity corrections based on verified readings rather than nominal temperature settings.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eUser-Tunable PID with Auto-Tuning\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Allows the thermal control system to be adjusted to laboratory ambient conditions through user-configurable PID parameters and automatic tuning.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003e304 Stainless Steel Tank and Specimen Clamp\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Provides corrosion resistance under continuous water exposure and repeated specimen clamping.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003e304 Stainless Steel Water Line Fittings\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Maintains a corrosion-resistant water flow path, reducing the risk of corrosion products contaminating specimens or affecting measurements.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eElectrostatic Powder-Coated Working Vessel\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Adds surface protection to the stainless steel vessel for reliable operation in humid laboratory environments.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003e\u003cspan\u003eTheory and Method\u003c\/span\u003e\u003c\/h2\u003e\n\u003cp\u003e\u003cspan\u003eWater flow perpendicular to a geotextile follows Darcy's law under laminar flow conditions, where the discharge rate remains proportional to the hydraulic gradient across the specimen. The QualiGTX™ GPT A establishes a defined hydraulic head difference across a clamped sample and measures the water volume passing through a fixed 50 mm aperture during a recorded time interval. Permittivity is calculated by dividing the discharge rate by the specimen area and hydraulic head, with the resulting value expressed in inverse seconds. Multiplying permittivity by the nominal specimen thickness converts the result into a permeability coefficient expressed in velocity units.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThe main challenge in achieving repeatable permeability measurements is controlling operator-dependent variations rather than simply obtaining an accurate reading. Differences in head height adjustment, measurement start and stop times, and visual judgments about when the water level becomes stable can all influence test results. The QualiGTX™ GPT A addresses these variables by automatically locating the zero water level, positioning the water at the programmed head, and controlling the collection interval using its internal timing system. Eliminating these three manual judgment points helps reduce measurement variation between technicians testing identical materials.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eMaintaining a constant hydraulic head is essential for applying Darcy's law throughout the measurement process. As water passes through the specimen, the supply level naturally decreases. This reduction changes the hydraulic gradient and can cause the flow rate to decline during testing. The QualiGTX™ GPT A regulates replacement water delivery at a controlled rate to maintain the selected water level and preserve consistent test conditions. Dissolved gases can also affect flow measurements because microbubbles within the geotextile pore structure may obstruct water pathways. The integrated dissolved oxygen analyzer therefore checks the water condition before measurement to help identify this potential source of interference.\u003c\/span\u003e\u003c\/p\u003e\n\u003ch2\u003eAutomatic Geotextile Permeability Tester - QualiGTX™ GPT A Technical Specifications\u003c\/h2\u003e\n\u003ctable class=\"table table-style-align-center\" align=\"center\" border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"498\"\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003e\u003cstrong\u003eParameter\u003c\/strong\u003e\u003c\/th\u003e\n\u003cth\u003e\u003cstrong\u003eSpecification\u003c\/strong\u003e\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eMaximum Head Differential\u003c\/td\u003e\n\u003ctd\u003e250 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSpecimen Clamp Inner Diameter\u003c\/td\u003e\n\u003ctd\u003eØ50 ± 0.5 mm (304 stainless steel)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMaximum Specimen Thickness\u003c\/td\u003e\n\u003ctd\u003e20 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTiming Range\u003c\/td\u003e\n\u003ctd\u003e0 to 9,999 s\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTiming Accuracy\u003c\/td\u003e\n\u003ctd\u003e0.1 s\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTemperature Measurement Range\u003c\/td\u003e\n\u003ctd\u003e0 °C to 110 °C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTemperature Control Range\u003c\/td\u003e\n\u003ctd\u003e10 °C to 60 °C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTemperature Control Accuracy\u003c\/td\u003e\n\u003ctd\u003e±0.5 °C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eThermometer Accuracy\u003c\/td\u003e\n\u003ctd\u003e0.1 °C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTemperature Correction Accuracy\u003c\/td\u003e\n\u003ctd\u003e±0.1 °C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDissolved Oxygen Range\u003c\/td\u003e\n\u003ctd\u003e0 to 20 mg\/L; 0 to 200 %; 0 to 400 hPa\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDissolved Oxygen Accuracy\u003c\/td\u003e\n\u003ctd\u003e±1.5 % FS\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDissolved Oxygen Repeatability\u003c\/td\u003e\n\u003ctd\u003e±0.5 % FS\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDissolved Oxygen Resolution\u003c\/td\u003e\n\u003ctd\u003e0.01 mg\/L; 0.1 %; 1 hPa\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWater Supply Tank Capacity\u003c\/td\u003e\n\u003ctd\u003e36 L\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTemperature Control Modes\u003c\/td\u003e\n\u003ctd\u003eCooling and heating\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCooling Method\u003c\/td\u003e\n\u003ctd\u003eCompressor unit\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTemperature Control\u003c\/td\u003e\n\u003ctd\u003ePID with auto-tuning\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCompressor Power\u003c\/td\u003e\n\u003ctd\u003e550 W\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInternal Circulation Pump Power\u003c\/td\u003e\n\u003ctd\u003e100 W\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCirculation Pump Flow Rate\u003c\/td\u003e\n\u003ctd\u003e15 L\/min\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTotal Power\u003c\/td\u003e\n\u003ctd\u003e1 kW\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDimensions (W × D × H)\u003c\/td\u003e\n\u003ctd\u003e1,150 × 670 × 1,580 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e180 kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e","brand":"Qualitest USA LC","offers":[{"title":"Default Title","offer_id":53459727221047,"sku":null,"price":100.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0786\/1859\/1543\/files\/automatic-geotextile-permeabilit.webp?v=1793363564"},{"product_id":"digital-geotextile-permeability-tester","title":"Digital Geotextile Permeability Tester","description":"\u003cdiv\u003e\n\u003cdiv\u003e\n\u003ch2\u003eDigital Geotextile Permeability Tester – QualiGTX™ GPT D\u003c\/h2\u003e\n\u003cp\u003eThe QualiGTX™ GPT D Digital Geotextile Permeability Tester measures vertical water flow through single-layer and multilayer geotextile specimens under no-load conditions. Qualitest North America designed this apparatus around ASTM D4491, the permittivity test method widely used by North American laboratories. Its 10-inch color touchscreen simplifies test configuration, timing, and result monitoring. It provides laboratories performing routine acceptance testing with standards-based measurements without requiring the investment in a fully automated testing system.\u003c\/p\u003e\n\u003cp\u003eThe instrument accommodates geotextile specimens up to 20 mm thick within a Ø50 mm high-strength 304 stainless steel clamping assembly. It applies a hydraulic head differential of up to 250 mm H₂O. The integrated heating and cooling system regulates water temperature from 5 °C to 60 °C, with a resolution of 0.1 °C. A dissolved oxygen measuring device verifies water conditions before testing, while automatic timing operates across a 999-second range.\u003c\/p\u003e\n\u003cp\u003eThe lateral two-unit water supply stabilization system quickly establishes the required water head and minimizes surface fluctuations, reducing the waiting time before measurements can begin. The unit features a compact 750 × 720 mm footprint, weighs 120 kg, and operates on standard single-phase 220 V power without requiring a dedicated utility connection. Its automatic water supply maintains a constant hydraulic head throughout data collection without manual refilling. This combination of controlled testing conditions and straightforward operation makes it a practical upgrade for laboratories transitioning from manual permeameters.\u003c\/p\u003e\n\u003ch2\u003eDigital Geotextile Permeability Tester – QualiGTX™ GPT D Applications\u003c\/h2\u003e\n\u003cp\u003eThe QualiGTX™ GPT D is suitable for laboratories requiring consistent, reliable geotextile permeability measurements for routine testing and quality verification rather than advanced research applications.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eGeotextile Manufacturing Quality Control: Performs routine production lot inspections to verify permittivity values against declared specifications before products are shipped.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eConstruction Materials Testing Laboratories: Supports acceptance testing of filter and separation geotextiles supplied for road, railway, and earthworks projects.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eContractor and Site Laboratories: Verifies that delivered geotextile materials comply with project specifications before installation in subgrades or drainage systems.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eDistributor and Importer Verification: Provides independent testing to confirm supplier declarations and assess incoming material shipments.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eHighway and Municipal Drainage Work: Evaluates water flow capacity in edge drain wraps, trench drainage fabrics, and separation layers.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eLandfill and Containment Projects: Checks whether drainage and protection geotextiles installed above liner systems satisfy specified design flow requirements.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eErosion Control and Slope Drainage: Tests filter fabrics installed behind revetments, gabions, and retaining structures.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eTechnical Colleges and University Laboratories: Provides practical instruction in the geotextile permittivity method using equipment aligned with the published testing procedure.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eProduct Development Screening: Enables preliminary comparisons of fiber types, basis weights, and bonding variables before undertaking comprehensive material characterization.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eStandards\u003c\/h2\u003e\n\u003cp\u003eThe QualiGTX™ GPT D complies with the apparatus requirements of the recognized North American test method for determining the water permeability of geotextiles in their uncompressed condition.\u003c\/p\u003e\n\u003cp\u003e- ASTM D4491 – Standard Test Methods for Water Permeability of Geotextiles by Permittivity\u003c\/p\u003e\n\u003ch2\u003eDigital Geotextile Permeability Tester – QualiGTX™ GPT D Key Features\u003c\/h2\u003e\n\u003cp\u003eThe QualiGTX™ GPT D combines touchscreen operation with a conditioned water supply in a compact, single-cell configuration. Its integrated controls simplify testing procedures and allow operators to concentrate on obtaining accurate measurements.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003e10-Inch Color Touchscreen Control: Combines test configuration, timing, and result monitoring on a single display, allowing technicians to view measurements directly without manually recording gauge readings.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eAutomatic Digital Timing: Controls the measurement interval using an internal clock across a 999-second range, eliminating timing errors associated with manual stopwatches.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eLateral Two-Unit Supply Stabilization: Quickly establishes the target hydraulic head and stabilizes the water surface, minimizing delays before measurements begin.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eAutomatic Water Supply: Maintains a consistent hydraulic head throughout the collection period without requiring manual water replenishment.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eControlled Temperature Water System: Heats or cools the water supply between 5 °C and 60 °C, supporting accurate correction of test results to the 20 °C reference temperature.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003e0.1 °C Temperature Resolution: Provides precise temperature readings to support the viscosity corrections required by the test method.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eDissolved Oxygen Measuring Device: Checks water conditions before testing and helps identify entrained air that could reduce measured flow by obstructing specimen pores.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eHigh-Strength 304 Stainless Steel Clamp: Secures and seals specimens consistently while providing resistance to corrosion and deformation during extended operation.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eIntegrated Source Water Tank: Supplies water to the test cell through an onboard reservoir, eliminating the need for a permanently connected water supply at the testing bench.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eDirect Result Display: Presents the calculated measurement upon test completion, allowing operators to proceed to the next specimen without performing separate calculations.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eCompact Single-Cell Frame: Requires only a 750 × 720 mm footprint and operates using standard single-phase 220 V power, making it suitable for laboratories without specialized utility connections.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eTheory and Method\u003c\/h2\u003e\n\u003cp\u003eWater flowing perpendicular to a geotextile's plane follows Darcy's law under laminar flow conditions. Accordingly, the discharge rate increases in proportion to the hydraulic head difference across the fabric. The QualiGTX™ GPT D secures the specimen within a Ø50 mm aperture, maintains a measured hydraulic head, and records the volume of water passing through the material over a specified time interval. The resulting discharge measurement, evaluated against the known hydraulic head, forms the basis of the test. The instrument maintains stable head conditions, water temperature, and water quality to minimize variations during measurement.\u003c\/p\u003e\n\u003cp\u003eThe test method determines permittivity, calculated by dividing the flow rate by the specimen area and then by the hydraulic head. The resulting value, expressed in reciprocal seconds (s⁻¹), characterizes the geotextile independently of its thickness. This is important because nominal specimen thickness can change during packaging, transportation, and handling, making thickness-dependent permeability coefficients less suitable for direct comparisons between fabrics. When required for design calculations, the permeability coefficient can be obtained by multiplying permittivity by the nominal specimen thickness.\u003c\/p\u003e\n\u003cp\u003eWater viscosity decreases as temperature increases. Consequently, measurements taken without temperature correction can reflect changes in water temperature as well as the actual characteristics of the geotextile. The test method standardizes results against a reference temperature of 20 °C, making reliable temperature measurement essential. The QualiGTX™ GPT D provides water heating and cooling between 5 °C and 60 °C, with temperature readings available at 0.1 °C resolution. Its dissolved oxygen measuring device provides an additional water quality check. Dissolved gases can escape from the water and form bubbles within the specimen, obstructing pores and reducing the measured flow rate. Verifying water conditions helps identify this potential source of measurement variation.\u003c\/p\u003e\n\u003ch2\u003eDigital Geotextile Permeability Tester - QualiGTX™ GPT D Technical Specifications\u003c\/h2\u003e\n\u003ctable class=\"table table-style-align-center\" align=\"center\" border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"800\"\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eParameter\u003c\/th\u003e\n\u003cth\u003eSpecification\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eMaximum Head Differential\u003c\/td\u003e\n\u003ctd\u003e250 mmH₂O (2,450 Pa)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSpecimen Clamp Inner Diameter\u003c\/td\u003e\n\u003ctd\u003eØ50 ± 0.5 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMaximum Specimen Thickness\u003c\/td\u003e\n\u003ctd\u003e20 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSpecimen Clamp Material\u003c\/td\u003e\n\u003ctd\u003eHigh-strength 304 stainless steel\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTiming Range\u003c\/td\u003e\n\u003ctd\u003e0 to 999 s\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTemperature Range\u003c\/td\u003e\n\u003ctd\u003e5 °C to 60 °C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTemperature Resolution\u003c\/td\u003e\n\u003ctd\u003e0.1 °C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTemperature Control\u003c\/td\u003e\n\u003ctd\u003eHeating and cooling\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDissolved Oxygen Measurement\u003c\/td\u003e\n\u003ctd\u003eIncluded\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eControl System\u003c\/td\u003e\n\u003ctd\u003e10-inch color touchscreen\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWater Supply\u003c\/td\u003e\n\u003ctd\u003eAutomatic, with source water tank\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eHead Stabilization\u003c\/td\u003e\n\u003ctd\u003eLateral two-unit stabilizing system\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eVoltage\u003c\/td\u003e\n\u003ctd\u003e220 V, 50 Hz (110V is also available)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDimensions (W × D × H)\u003c\/td\u003e\n\u003ctd\u003e750 × 720 × 1,750 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e120 kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e","brand":"Qualitest USA LC","offers":[{"title":"Default Title","offer_id":53459730530615,"sku":null,"price":100.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0786\/1859\/1543\/files\/entry-level-geotextile-permeabil.webp?v=1793363783"},{"product_id":"geosynthetic-permeability-tester","title":"Geosynthetic Permeability Tester","description":"\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003ch2\u003eGeosynthetic Permeability Tester – QualiGTX™ GPT GS\u003c\/h2\u003e\n\u003cp\u003eThe QualiGTX™ GPT GS Geosynthetic Permeability Tester measures water flow perpendicular to the plane of geotextiles, nonwoven fabrics, and other geosynthetic materials under unloaded conditions. Qualitest North America designed this apparatus in accordance with ISO 11058, which specifies permeability reporting in terms of flow velocity rather than permittivity. Its 10-inch color touchscreen provides centralized control of test setup, timing, and measurement results. This allows laboratories following European and international specifications to obtain results in the required format without additional processing.\u003c\/p\u003e\n\u003cp\u003eThe specimen clamping assembly accommodates a Ø50 mm sample and features high-strength 304 stainless steel components. An integrated source water tank supplies the test cell without requiring a permanent plumbing connection. The heating and cooling system maintains water temperatures from 5 °C to 60 °C, with a display resolution of 0.1 °C. A built-in dissolved oxygen analyzer measures concentrations from 0 to 20 mg\/L with 0.01 mg\/L resolution, documenting water conditions before testing. Automatic timing supports intervals up to 999 seconds, with results displayed immediately after each test.\u003c\/p\u003e\n\u003cp\u003eWith a height of 1,750 mm and a footprint of 750 × 720 mm, the instrument weighs 120 kg and operates on single-phase 220 V power. Installation does not require three-phase electricity, compressed air, or a dedicated laboratory water supply. Its compact configuration occupies approximately the space of a single-cell permeameter rather than a large floor-standing automated system. Laboratories testing geocomposites, drainage fabrics, filter media, and conventional geotextiles can use the QualiGTX™ GPT GS as a dedicated station for measuring cross-plane water flow.\u003c\/p\u003e\n\u003ch2\u003eGeosynthetic Permeability Tester – QualiGTX™ GPT GS Applications\u003c\/h2\u003e\n\u003cp\u003eThe QualiGTX™ GPT GS is designed for laboratories conducting permeability evaluations in accordance with international specifications across a broad range of geosynthetic materials, including geotextiles and related products.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eGeosynthetic Product Certification: Determines the velocity index for CE marking submissions and international product declarations.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eNonwoven and Composite Drainage Media: Measures cross-plane water flow through geocomposites, drainage cores, and laminated filter layers.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eExport-Oriented Geotextile Production: Supports batch testing according to methods specified by European and Middle Eastern customers.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eRoad, Rail, and Earthworks Contracting: Verifies the performance of separation and filtration materials supplied for projects governed by international specifications.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eCoastal and Hydraulic Structures: Evaluates the flow capacity of filter fabrics installed behind revetments, seawalls, and canal linings.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eLandfill Engineering: Assesses protective and drainage geosynthetics installed above barrier systems.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eFiltration and Technical Textiles: Performs permeability screening of filter media, sinter plates, and porous sheet materials used beyond civil engineering applications.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eIndependent Testing Houses: Supports arbitration and referee testing when clients explicitly require compliance with the international test method.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eResearch and Materials Development: Examines relationships between pore structure, bonding processes, and measured water flow velocity.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eStandards\u003c\/h2\u003e\n\u003cp\u003eThe QualiGTX™ GPT GS complies with the apparatus requirements of the international test method for determining the water permeability of geosynthetics perpendicular to their plane. Testing is performed on a single material layer without an applied load.\u003c\/p\u003e\n\u003cp\u003e- ISO 11058 – Geotextiles and Geotextile-Related Products: Determination of Water Permeability Characteristics Normal to the Plane, Without Load.\u003c\/p\u003e\n\u003ch2\u003eGeosynthetic Permeability Tester – QualiGTX™ GPT GS Key Features\u003c\/h2\u003e\n\u003cp\u003eThe QualiGTX™ GPT GS combines touchscreen operation, controlled water temperature, and water quality monitoring in a compact, single-cell testing system.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003e10-Inch Color Touchscreen Control: Integrates test configuration, timing, and measurement readouts into one interface, allowing technicians to monitor displayed values without relying on separate gauges or worksheets.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eAutomatic Digital Timing: Measures collection intervals automatically across a range of up to 999 seconds, minimizing operator reaction-time effects during testing.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eHeating and Cooling Temperature Control: Adjusts the water supply to temperatures between 5 °C and 60 °C, enabling consistent testing conditions throughout the year.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003e0.1 °C Temperature Display Resolution: Provides precise temperature readings to support viscosity correction to the 20 °C reference temperature.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eDissolved Oxygen Analyzer: Measures oxygen concentration in mg\/L, percentage saturation, and partial pressure, with an accuracy of ±1.5 % FS, adding water condition data to the test record.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eHigh-Strength 304 Stainless Steel Clamp: Secures specimens through repeated sealing cycles while resisting corrosion and deformation.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eIntegrated Source Water Tank: Feeds the testing cell from an onboard reservoir, eliminating the need for a permanent water supply connection.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eDirect Result Display: Shows the calculated measurement immediately after test completion, allowing operators to proceed directly to the next specimen.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cp\u003eCompact Floor Frame: Features a 750 × 720 mm footprint and operates on standard 220 V single-phase power, making it suitable for laboratories with limited utility connections.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eTheory and Method\u003c\/h2\u003e\n\u003cp\u003eCross-plane permeability measures the ability of water to pass through the thickness of a geosynthetic material rather than flow along its surface. The QualiGTX™ GPT GS creates a hydraulic head difference across a clamped specimen and measures the resulting discharge. According to Darcy's law, discharge remains proportional to the hydraulic head while the flow is laminar. Dividing the measured discharge by the specimen area determines the flow velocity in millimeters per second. Since ISO 11058 specifies flow velocity as the reporting parameter, the result is not divided by the hydraulic head.\u003c\/p\u003e\n\u003cp\u003eThe test method provides two measurement approaches: constant head and falling head. For constant head testing, the operator maintains a specified head loss, typically 70 mm, together with additional levels ranging from 20% to 80% of that value. The relationship between head loss and flow velocity is then plotted. In the falling head procedure, water levels equalize across the specimen while the apparatus measures the time required for the corresponding water level change. For routine quality control of materials with previously established characteristics, the velocity index measured at a 50 mm head loss is sufficient.\u003c\/p\u003e\n\u003cp\u003eTemperature is an important factor in converting raw measurements into reportable results. ISO 11058 adjusts flow velocity to the reference temperature of 20 °C using the viscosity ratio between the actual test temperature and the reference temperature. Consequently, unstable water temperature can compromise the accuracy of this correction. The QualiGTX™ GPT GS maintains water temperatures between 5 °C and 60 °C and provides readings at 0.1 °C resolution. Trapped and dissolved air can introduce another source of systematic measurement error, making the instrument's integrated dissolved oxygen analyzer an important part of the testing system.\u003c\/p\u003e\n\u003ch2\u003eGeosynthetic Permeability Tester - QualiGTX™  GPT GS Technical Specifications\u003c\/h2\u003e\n\u003ctable class=\"table table-style-align-center\" align=\"center\" border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"489\"\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eParameter\u003c\/th\u003e\n\u003cth\u003eSpecification\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eSpecimen Clamp Diameter\u003c\/td\u003e\n\u003ctd\u003eØ50 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSpecimen Clamp Material\u003c\/td\u003e\n\u003ctd\u003eHigh-strength 304 stainless steel\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTiming Range\u003c\/td\u003e\n\u003ctd\u003e0 to 999 s\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTemperature Range\u003c\/td\u003e\n\u003ctd\u003e5 °C to 60 °C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTemperature Resolution\u003c\/td\u003e\n\u003ctd\u003e0.1 °C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTemperature Control\u003c\/td\u003e\n\u003ctd\u003eHeating and cooling\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDissolved Oxygen Range\u003c\/td\u003e\n\u003ctd\u003e0 to 20 mg\/L; 0 to 200 %; 0 to 400 hPa\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDissolved Oxygen Accuracy\u003c\/td\u003e\n\u003ctd\u003e±1.5 % FS\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDissolved Oxygen Repeatability\u003c\/td\u003e\n\u003ctd\u003e±0.5 % FS\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDissolved Oxygen Resolution\u003c\/td\u003e\n\u003ctd\u003e0.01 mg\/L; 0.1 %; 1 hPa\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eControl System\u003c\/td\u003e\n\u003ctd\u003e10-inch color touchscreen\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWater Supply\u003c\/td\u003e\n\u003ctd\u003eSource water tank\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eVoltage\u003c\/td\u003e\n\u003ctd\u003e220 V, 50 Hz (110V is also available)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDimensions (W × D × H)\u003c\/td\u003e\n\u003ctd\u003e750 × 720 × 1,750 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e120 kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e","brand":"Qualitest USA LC","offers":[{"title":"Default Title","offer_id":53459733348663,"sku":null,"price":100.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0786\/1859\/1543\/files\/geosynthetic-permeability-tester.webp?v=1793364001"},{"product_id":"geomembrane-permeability-tester","title":"Geomembrane Permeability Tester","description":"\u003ch2\u003e\u003cspan\u003eGeomembrane Permeability Tester – QualiGTX™ GPT GM 100\u003c\/span\u003e\u003c\/h2\u003e\n\u003cp\u003e\u003cspan\u003eThe QualiGTX™ GPT GM 100 geomembrane permeability tester determines the permeability coefficient of waterproofing membranes under controlled hydraulic pressure. Supplied by Qualitest North America, this instrument is designed for laboratories evaluating barrier liner performance, where extremely low permeability values require precise and reliable measurement. It provides a pump-controlled pressure range of 0 to 1 MPa and accommodates three specimens simultaneously. A 10-inch LCD touchscreen simplifies test configuration, pressure adjustment, and automatic timing.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eUnlike geotextiles, which allow water to pass through relatively quickly and can be evaluated within seconds, geomembranes are designed to restrict water transmission to extremely low levels. Consequently, their permeability tests may require several hours. The QualiGTX™ GPT GM 100 uses applied hydraulic pressure rather than gravity head to drive water through a Ø80 mm specimen, providing an exposed flow area greater than 20 cm². The permeability coefficient is calculated using the collected water volume and elapsed test time.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eWith three specimen positions operating simultaneously, the instrument generates replicate test data within a single testing cycle, eliminating the need for three separate runs. The water collector is available in Ø70 mm or Ø100 mm configurations, selected when ordering. A source water tank is included as standard, while a controllable constant-temperature water supply is available as a custom option. The unit features a 750 × 720 mm footprint, weighs 110 kg, and operates on 220 V single-phase power.\u003c\/span\u003e\u003c\/p\u003e\n\u003ch2\u003e\u003cspan\u003eGeomembrane Permeability Tester – QualiGTX™ GPT GM 100 Applications\u003c\/span\u003e\u003c\/h2\u003e\n\u003cp\u003e\u003cspan\u003eThe QualiGTX™ GPT GM 100 is suitable for laboratories assessing containment barrier performance, where liner integrity is critical and failures can result in substantial remediation expenses.\u003c\/span\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eLandfill Liner Systems\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Evaluates the permeability of primary and secondary barrier membranes before installation over subgrade and drainage layers.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eMining and Tailings Containment\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Qualifies geomembrane liners used in heap leach pads, process ponds, and tailings storage facilities.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eWater Storage and Canal Lining\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Tests waterproofing membranes specified for reservoirs, irrigation canals, and potable water containment applications.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eGeomembrane Manufacturing Quality Control\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Supports batch release testing of HDPE, LLDPE, PVC, and reinforced sheets against declared performance requirements.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eEnvironmental Remediation Projects\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Verifies the barrier properties of cap and cut-off materials used at contaminated sites.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eTunnel and Underground Waterproofing\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Assesses membranes designed to prevent groundwater penetration into underground structures.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eAquaculture and Agricultural Ponds\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Confirms liner performance in applications where seepage can result in direct operating costs.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eRoofing and Building Waterproofing\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Screens sheet membranes used in below-grade waterproofing and roof assemblies.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eThird-Party Testing Laboratories\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Provides independent verification of manufacturer performance declarations for tender submissions and acceptance documentation.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003e\u003cspan\u003eGeomembrane Permeability Tester – QualiGTX™ GPT GM 100 Key Features\u003c\/span\u003e\u003c\/h2\u003e\n\u003cp\u003e\u003cspan\u003eThe QualiGTX™ GPT GM 100 integrates pump-controlled hydraulic pressure, simultaneous testing of multiple specimens, and touchscreen operation in a compact floor-standing design.\u003c\/span\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003e0 to 1 MPa Adjustable Pressure Range\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Accommodates applications ranging from low-pressure screening to full-pressure qualification, allowing laboratories to evaluate different liner specifications using one instrument.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eThree Parallel Specimen Positions\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Tests three specimens simultaneously to generate replicate results and reduce the elapsed time of a three-specimen testing campaign to approximately one-third.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eAutomatic Pressure Pump Supply\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Maintains the selected pressure throughout the water collection period without requiring manual adjustments during extended tests.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eSelectable Ø70 mm or Ø100 mm Collector\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Provides two collector diameter options to suit the material being tested and its expected water transmission rate. The configuration is selected when ordering.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eØ80 mm Specimen with Over 20 cm² Flow Area\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Provides a sufficiently large exposed testing area to collect measurable water volumes from low-permeability membranes.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003e10-Inch LCD Touchscreen Control\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Combines pressure configuration, test operation, result display, and automatic digital timing through an integrated touchscreen interface.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003e304 Stainless Steel Specimen Clamp\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Secures the membrane and maintains a reliable seal under full test pressure while resisting corrosion during repeated exposure to water.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eStandard Source Water Tank\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Supplies the pump through an integrated water reservoir, eliminating the need for a direct plumbed water connection during installation.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eOptional Temperature-Controlled Water Supply\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Available as a custom configuration for laboratories requiring water supplied at a controlled temperature.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eCompact 110 kg Frame\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Features a 750 × 720 mm footprint and 220 V single-phase operation, making it suitable for laboratories without dedicated utility services.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003e\u003cspan\u003eTheory and Method\u003c\/span\u003e\u003c\/h2\u003e\n\u003cp\u003e\u003cspan\u003eGeomembranes are engineered to prevent advective water flow. As a result, water transmission through these materials follows a different mechanism from the flow observed in porous fabrics. Water first dissolves into the polymer at the upstream surface, diffuses through the membrane along a concentration gradient, and then desorbs from the downstream surface. This solution-diffusion process produces extremely low flux levels, often several orders of magnitude below those associated with conventional pore flow. Accordingly, the measured result represents an equivalent permeability coefficient rather than a direct pore-flow property.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eApplying hydraulic pressure makes this low-level transmission measurable. Increasing the driving pressure to 1 MPa raises the water flux approximately in proportion to the applied pressure, allowing measurable volumes to pass through materials that transmit almost no water under gravity head. The QualiGTX™ GPT GM 100 uses a pump to maintain the selected pressure, adjustable from 0 to 1 MPa, across the specimen throughout the test. The permeability coefficient is then determined from the collected water volume, exposed specimen area, membrane thickness, and applied pressure using the Darcy relationship.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eReplicate testing is particularly important when evaluating geomembrane permeability. Variations in sheet thickness, along with localized defects such as pinholes or unusually thin areas, can cause individual specimens to produce results that do not represent the material's intended performance. Testing three specimens simultaneously helps identify this variation within one testing cycle rather than requiring three separate runs. The 304 stainless steel specimen clamp maintains the seal under full hydraulic pressure, preventing leakage at the clamping surface from being mistaken for water transmission through the membrane.\u003c\/span\u003e\u003c\/p\u003e\n\u003ch2\u003eGeomembrane Permeability Tester - QualiGTX™ GPT GM 100 Technical Specifications\u003c\/h2\u003e\n\u003ctable class=\"table table-style-align-center\" align=\"center\" border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"590\"\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eParameter\u003c\/th\u003e\n\u003cth\u003eSpecification\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eMaximum Pressure\u003c\/td\u003e\n\u003ctd\u003e1 MPa\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePressure Adjustment Range\u003c\/td\u003e\n\u003ctd\u003e0 to 1 MPa\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWater Collector Diameter\u003c\/td\u003e\n\u003ctd\u003eØ70 mm or Ø100 mm (selected at order)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSpecimen Size\u003c\/td\u003e\n\u003ctd\u003eØ80 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eExposed Flow Area\u003c\/td\u003e\n\u003ctd\u003eGreater than 20 cm²\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSpecimen Positions\u003c\/td\u003e\n\u003ctd\u003e3\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWater Supply\u003c\/td\u003e\n\u003ctd\u003eAutomatic pressure pump, source water tank\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSpecimen Clamp Material\u003c\/td\u003e\n\u003ctd\u003e304 stainless steel\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eControl System\u003c\/td\u003e\n\u003ctd\u003e10-inch LCD touchscreen with automatic digital timing\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTemperature-Controlled Supply\u003c\/td\u003e\n\u003ctd\u003eOptional, custom order\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eVoltage\u003c\/td\u003e\n\u003ctd\u003e220 V (110V is also available)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDimensions (W × D × H)\u003c\/td\u003e\n\u003ctd\u003e750 × 720 × 1,750 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e110 kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e","brand":"Qualitest USA LC","offers":[{"title":"Default Title","offer_id":53459735839031,"sku":null,"price":100.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0786\/1859\/1543\/files\/geomembrane-permeability-tester1.webp?v=1793364168"},{"product_id":"motorized-geosynthetic-permeability-tester","title":"Motorized Geosynthetic Permeability Tester","description":"\u003ch2\u003e\u003cspan\u003eMotorized Geosynthetic Permeability Tester – QualiGTX™ GPT M\u003c\/span\u003e\u003c\/h2\u003e\n\u003cp\u003e\u003cspan\u003eThe QualiGTX™ GPT M motorized geosynthetic permeability tester measures vertical water flow through geotextiles, geocomposites, and other related materials using automated hydraulic head adjustment. Qualitest North America designed the motorized water level control to simplify constant-head testing, which requires measurements at multiple hydraulic head heights. Manually repositioning an overflow between readings takes additional time and can affect repeatability. The integrated control system automatically moves the water level to each selected setting, while the 10-inch touchscreen provides convenient access to test configuration, timing, and flow volume readings.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eDesigned for laboratories conducting tests to hydraulic engineering specifications, the QualiGTX™ GPT M provides permeability data for seepage calculations and engineering analysis rather than simple pass-or-fail evaluations. Its specimen clamp features a 20 cm² test area constructed from 304 stainless steel. An integrated supply tank automatically maintains the water supply throughout collection. The heating and cooling system regulates water temperature from 5 °C to 60 °C, with a display resolution of 0.1 °C. Additionally, a dissolved oxygen analyzer measures concentrations from 0 to 20 mg\/L to document water conditions before testing.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThe tester digitally displays the volume of water passing through the specimen during the test and provides automatic timing up to 999 s. Its cabinet dimensions of 750 × 720 mm match the other equipment in the QualiGGTE bench range. The system operates on 220 V single-phase power, with the motorized head assembly bringing its total weight to 150 kg. Installation requires neither compressed air nor a dedicated water supply line. For laboratories performing permeability measurements at multiple hydraulic head levels, automated adjustment significantly reduces testing time and manual intervention.\u003c\/span\u003e\u003c\/p\u003e\n\u003ch2\u003e\u003cspan\u003eMotorized Geosynthetic Permeability Tester – QualiGTX™ GPT M Applications\u003c\/span\u003e\u003c\/h2\u003e\n\u003cp\u003e\u003cspan\u003eThe QualiGTX™ GPT M is designed for laboratories supporting water infrastructure and hydraulic engineering projects, where geosynthetic permeability measurements provide essential input for engineering design and seepage calculations.\u003c\/span\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eDam and Reservoir Engineering\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Evaluating filter and drainage geosynthetics against seepage models for embankments and core zones.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eCanal and Irrigation Systems\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Measuring the flow capacity of lining and drainage layers exposed to continuous water loss risks.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eWater Conservancy Project Laboratories\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Conducting tests according to hydraulic engineering specifications that require multi-point hydraulic head data in reported results.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eFlood Defense and Levee Construction\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Assessing filter fabrics installed behind revetments, toe drains, and cut-off structures.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eHydropower Civil Works\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Qualifying drainage and separation materials used in headrace, tailrace, and spillway construction.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eGeocomposite Drainage Products\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Measuring cross-plane water flow through laminated and multilayer drainage materials.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eGeosynthetics Manufacturing\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Performing production quality testing and providing complete head-versus-flow curves with technical datasheets.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eConsulting and Design Laboratories\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Generating permeability data for seepage and filtration analysis involving water-retaining structures.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eResearch and Method Development\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Studying hydraulic flow behavior across different hydraulic gradients in newly developed material constructions.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003e\u003cspan\u003eMotorized Geosynthetic Permeability Tester – QualiGTX™ GPT M Key Features\u003c\/span\u003e\u003c\/h2\u003e\n\u003cp\u003e\u003cspan\u003eThe QualiGTX™ GPT M simplifies multi-point permeability testing through automated hydraulic head adjustment, integrated water conditioning, and touchscreen operation. Its features help laboratories maintain consistent testing conditions while reducing manual procedures.\u003c\/span\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eMotorized Water Level Adjustment\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Automatically moves the hydraulic head to each programmed height without manual repositioning, allowing multi-level permeability testing to proceed as a continuous sequence rather than requiring repeated manual setups.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eAutomatic Water Supply with Source Tank\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Supplies the test cell from an integrated reservoir during water collection, maintaining the required water level without continuous manual replenishment.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003e10-Inch Touchscreen Control\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Combines hydraulic head settings, test timing, and measurement results on one interface, helping maintain consistent procedures between operators.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eAutomatic Digital Timing\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Provides automatic collection timing across a range of up to 999 s, reducing measurement variations caused by operator reaction time.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eDigital Flow Volume Display\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Displays the volume of water passing through the specimen throughout the test, allowing operators to monitor measurement progress in real time.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eHeating and Cooling Temperature Control\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Regulates water temperature between 5 °C and 60 °C, providing stable and controlled conditions for subsequent correction to the 20 °C reference temperature.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003e0.1 °C Temperature Resolution\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Provides precise temperature readings to support reliable water viscosity correction during permeability calculations.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eDissolved Oxygen Analyzer\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Measures and reports dissolved oxygen in mg\/L, percent saturation, and partial pressure, with an accuracy of ±1.5 % FS, allowing water quality conditions to be documented in the test record.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003e304 Stainless Steel Specimen Clamp\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Provides a consistent seal around the 20 cm² test area while resisting corrosion and dimensional distortion during continuous exposure to water.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eStandard Bench Footprint\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Features a 750 × 720 mm cabinet and operates on 220 V single-phase power, matching the other equipment in the QualiGGTE permeability testing range for convenient laboratory layout planning.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003e\u003cspan\u003eTheory and Method\u003c\/span\u003e\u003c\/h2\u003e\n\u003cp\u003e\u003cspan\u003eVertical permeability testing evaluates the relationship between hydraulic head and the resulting water flow through a geosynthetic specimen rather than relying on a single measurement. Constant-head testing establishes this relationship by maintaining different hydraulic head levels in sequence and recording the corresponding discharge at each setting. Plotting hydraulic head against flow velocity and fitting a line through the origin provides a more reliable basis for determining the permeability coefficient than relying on an individual reading at one head height. The QualiGTX™ GPT M uses motorized adjustment to reach each selected head level automatically, making multi-point measurements more practical and efficient.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThe resulting plot also helps determine whether the specimen continues to follow Darcy's law. Under Darcy flow conditions, the relationship remains linear: doubling the hydraulic gradient produces twice the discharge. However, highly open, coarse geosynthetic materials may allow water to pass rapidly enough for turbulent flow to develop at higher hydraulic heads. When this occurs, the plot deviates from its linear pattern. Identifying this change requires measurements across multiple head levels, demonstrating the practical advantage of motorized adjustment compared with a fixed overflow arrangement.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eTwo additional conditions must remain controlled during permeability measurements. First, water viscosity decreases as temperature increases, making correction to the 20 °C reference temperature necessary. Accurate correction depends on reliable temperature measurement. The QualiGTX™ GPT M provides 0.1 °C display resolution across its operating temperature range of 5 °C to 60 °C. Second, dissolved air must be considered because gas released from the water can form bubbles inside the specimen's pores, restricting flow and reducing measured permeability. The integrated dissolved oxygen analyzer records this water condition before the collection process begins.\u003c\/span\u003e\u003cspan\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003ch2\u003eMotorized Geosynthetic Permeability Tester - QualiGTX™ GPT M Technical Specifications\u003c\/h2\u003e\n\u003ctable class=\"table table-style-align-center\" align=\"center\" border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"558\"\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eParameter\u003c\/th\u003e\n\u003cth\u003eSpecification\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eTest Area\u003c\/td\u003e\n\u003ctd\u003e20 cm²\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSpecimen Clamp Material\u003c\/td\u003e\n\u003ctd\u003e304 stainless steel\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWater Level Adjustment\u003c\/td\u003e\n\u003ctd\u003eMotorized\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTiming Range\u003c\/td\u003e\n\u003ctd\u003e0 to 999 s\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTemperature Range\u003c\/td\u003e\n\u003ctd\u003e5 °C to 60 °C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTemperature Resolution\u003c\/td\u003e\n\u003ctd\u003e0.1 °C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTemperature Control\u003c\/td\u003e\n\u003ctd\u003eHeating and cooling\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDissolved Oxygen Range\u003c\/td\u003e\n\u003ctd\u003e0 to 20 mg\/L; 0 to 200 %; 0 to 400 hPa\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDissolved Oxygen Accuracy\u003c\/td\u003e\n\u003ctd\u003e±1.5 % FS\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDissolved Oxygen Repeatability\u003c\/td\u003e\n\u003ctd\u003e±0.5 % FS\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDissolved Oxygen Resolution\u003c\/td\u003e\n\u003ctd\u003e0.01 mg\/L; 0.1 %; 1 hPa\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eControl System\u003c\/td\u003e\n\u003ctd\u003e10-inch touchscreen with automatic digital timing\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWater Supply\u003c\/td\u003e\n\u003ctd\u003eAutomatic, with source water tank\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eVoltage\u003c\/td\u003e\n\u003ctd\u003e220 V, 50 Hz (110V is also available)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDimensions (W × D × H)\u003c\/td\u003e\n\u003ctd\u003e750 × 720 × 1,750 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e150 kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e","brand":"Qualitest USA LC","offers":[{"title":"Default Title","offer_id":53459741737271,"sku":null,"price":100.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0786\/1859\/1543\/files\/motorized-geosynthetic-permeabil.webp?v=1793364335"},{"product_id":"manual-geotextile-permeability-tester-constant-head","title":"Manual Geotextile Permeability Tester (Constant Head)","description":"\u003ch2\u003e\u003cspan\u003eManual Geotextile Permeability Tester (Constant Head) – QualiGTX™ GPT MN\u003c\/span\u003e\u003c\/h2\u003e\n\u003ch4\u003e\u003cspan\u003eConstant Head Permittivity Apparatus for Single-Layer Geotextiles\u003c\/span\u003e\u003c\/h4\u003e\n\u003cp\u003e\u003cspan\u003eThe QualiGTX™ GPT MN Manual Geotextile Permeability Tester determines the rate of water flow perpendicular to a single geotextile layer under a constant hydraulic head. A specimen clamp with a ø50 ± 0.5 mm bore secures the fabric across the flow path. Water passes through the specimen under a head differential of up to 250 mm, while the discharged volume is collected in a 1000 mL graduated cylinder and measured using a timer with 0.01 s resolution. Based on the collected volume, elapsed time, test area, and hydraulic head, laboratories can calculate the permeability coefficient and permittivity.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eDesigned for manual operation, this model allows technicians to control the valves, measure the collected water volume, and record test times directly. This straightforward configuration simplifies maintenance and verification. Laboratories conducting occasional permeability checks for quality confirmation, rather than continuous testing throughout production shifts, can obtain reliable measurements without the additional expense and calibration requirements of an automated system.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThe specimen clamp accommodates materials up to 20 mm thick, making the apparatus suitable for heavy needle-punched nonwovens as well as thin woven and composite geotextiles. An integrated thermometer covering 0 to 50 °C monitors water temperature within the flow circuit. Since water viscosity changes with temperature, test results are normalized to a reference temperature before reporting. The complete unit requires a benchtop area of 500 × 550 mm and has a total weight of 36 kg.\u003c\/span\u003e\u003c\/p\u003e\n\u003ch2\u003e\u003cspan\u003eManual Geotextile Permeability Tester (Constant Head) – QualiGTX™ GPT MN Applications\u003c\/span\u003e\u003c\/h2\u003e\n\u003cp\u003e\u003cspan\u003eThe QualiGTX™ GPT MN is designed for laboratories evaluating the filtration and drainage characteristics of geotextile materials for manufacturing quality control, material procurement, and engineering design verification.\u003c\/span\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eNonwoven Geotextile Manufacturing\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Evaluates whether needle-punched and thermally bonded filter fabrics provide the water flow capacity specified in their product data sheets.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eWoven Geotextile Production\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Measures perpendicular water flow through woven filtration and separation fabrics, where the available open area influences hydraulic performance.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eDrainage System Design Verification\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Provides engineers with the flow measurements required to determine suitable filter layer dimensions behind retaining walls, along edge drains, and within blanket drainage systems.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eLandfill Leachate Collection\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Verifies the water flow capacity of filter geotextiles installed above drainage layers in landfill collection and cap systems.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eCoastal and Erosion Control Works\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Tests geotextile fabrics placed beneath riprap, gabions, and revetments, where inadequate filtration can result in soil loss.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eRoad and Railway Subgrade Drainage\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Assesses separation geotextiles designed to allow water passage while retaining fine soil particles under repeated loading conditions.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eContractor Incoming Inspection\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Checks delivered geotextile rolls against specified contract flow requirements before installation.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eThird-Party Testing Laboratories\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Provides cross-plane permeability testing capabilities through an apparatus that is straightforward to calibrate and suitable for audit verification.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003e\u003cspan\u003eManual Geotextile Permeability Tester (Constant Head) – QualiGTX™ GPT MN Key Features\u003c\/span\u003e\u003c\/h2\u003e\n\u003cp\u003e\u003cspan\u003eThe QualiGTX™ GPT MN features a straightforward hydraulic circuit and measurement arrangement designed to simplify constant-head permeability testing.\u003c\/span\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eConstant Head Operation\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Maintains a consistent hydraulic head throughout the test, allowing the discharge rate to stabilize and supporting repeatable measurements across different operators.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003e250 mm Maximum Head Differential\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Accommodates the lower head settings required by filtration testing methods while providing additional capacity for higher-gradient testing of dense geotextile fabrics.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eø50 ± 0.5 mm Specimen Clamp\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Establishes a defined testing area through a precisely controlled bore diameter, ensuring accurate area values for permeability calculations.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003e20 mm Specimen Thickness Capacity\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Supports thick needle-punched nonwoven and composite geotextile specimens without requiring clamp modifications.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003e1000 mL Graduated Cylinder\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Provides sufficient collection capacity for measuring discharge over a meaningful time interval, minimizing the proportion of timing error in the final result.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eTimer Resolving to 0.01 s\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Measures elapsed test time with the precision required to maintain accuracy during short-duration, high-flow tests.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eIntegrated 0 to 50 °C Thermometer\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Monitors water temperature during testing to support the viscosity correction needed for standardized reporting.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eManual Valve and Reading Control\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Allows technicians to manage test operations directly, simplifying troubleshooting and reducing calibration requirements.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eCompact Benchtop Frame\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Features a 500 × 550 mm footprint and a total weight of 36 kg, allowing convenient placement while preserving workspace for specimen preparation.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003e\u003cspan\u003eTheory and Method\u003c\/span\u003e\u003c\/h2\u003e\n\u003cp\u003e\u003cspan\u003eWater flow through geotextile materials is governed by Darcy's law, which describes the relationship between flow velocity and hydraulic gradient using a coefficient that characterizes the material's permeability. Flow velocity is determined by dividing the measured discharge by the clamped specimen area. The ø50 mm bore provides a defined testing area of approximately 19.6 cm², ensuring that all collected water passes through a known cross-sectional area. The hydraulic gradient is calculated by dividing the applied head differential by the specimen thickness. By rearranging Darcy's law, the permeability coefficient can be calculated directly from the measured water volume, elapsed time, test area, hydraulic head, and specimen thickness.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eSpecimen thickness presents a particular challenge when measuring water flow perpendicular to geotextile fabrics, which is why permittivity is also used as an independent performance parameter. Nonwoven geotextiles can compress under applied pressure, meaning their thickness varies according to the load acting on the material. Permittivity addresses this limitation by expressing water flow per unit area under a unit hydraulic head, eliminating specimen thickness from the calculation. Both the permeability coefficient and permittivity can therefore be determined from the same test performed with this apparatus. Laboratories can report the appropriate parameter according to the applicable specification.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eAccurate results depend on controlling two important testing conditions. The first is water viscosity, which decreases as temperature increases. Consequently, the same geotextile specimen can allow more water to pass when tested with warmer water than when tested under colder conditions. The integrated thermometer monitors water temperature so the measured results can be corrected to a reference temperature.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThe second consideration is dissolved air in the water. As water heats up inside the apparatus, dissolved air can escape from the solution and become trapped within the geotextile's pore structure. This gradually restricts water flow and can cause measured readings to decrease as testing continues. Using deaired water prevents this issue. Maintaining a constant hydraulic head also ensures consistent driving pressure, allowing the discharge rate to stabilize before the operator begins recording the test time.\u003c\/span\u003e\u003cspan\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003ch2\u003eManual Geotextile Permeability Tester (Constant Head) – QualiGTX™ GPT MN Technical Specifications\u003c\/h2\u003e\n\u003cdiv\u003e\n\u003ctable class=\"table table-style-align-center\" align=\"center\" border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"549\"\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eParameter\u003c\/th\u003e\n\u003cth\u003eSpecification\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eTest Method\u003c\/td\u003e\n\u003ctd\u003eConstant head, cross-plane (vertical) water flow\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMaximum Head Differential\u003c\/td\u003e\n\u003ctd\u003e250 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSpecimen Clamp Inner Diameter\u003c\/td\u003e\n\u003ctd\u003eø50 ± 0.5 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMaximum Specimen Thickness\u003c\/td\u003e\n\u003ctd\u003e20 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTimer Range\u003c\/td\u003e\n\u003ctd\u003e0 to 99.99 s\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eThermometer Range\u003c\/td\u003e\n\u003ctd\u003e0 to 50 °C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eGraduated Cylinder\u003c\/td\u003e\n\u003ctd\u003e1000 mL\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eVoltage\u003c\/td\u003e\n\u003ctd\u003e220 V (110V is also available)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDimensions (W × D × H)\u003c\/td\u003e\n\u003ctd\u003e500 × 550 × 600 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eNet Weight\u003c\/td\u003e\n\u003ctd\u003e36 kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e","brand":"Qualitest USA LC","offers":[{"title":"Default Title","offer_id":53459742490935,"sku":null,"price":100.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0786\/1859\/1543\/files\/manual-geotextile-permeability-t.webp?v=1793364514"},{"product_id":"geotextile-water-permeability-tester","title":"Geotextile Water Permeability Tester","description":"\u003ch2\u003e\u003cspan\u003eGeotextile Water Permeability Tester – QualiGTX™ GPT GW\u003c\/span\u003e\u003c\/h2\u003e\n\u003ch4\u003e\u003cspan\u003eTouchscreen Vertical Permeability Apparatus for Geosynthetic Materials\u003c\/span\u003e\u003c\/h4\u003e\n\u003cp\u003e\u003cspan\u003eThe QualiGTX™ GPT GW geotextile water permeability tester evaluates water flow perpendicular to geosynthetic materials using ø80 mm test specimens. Its large color touchscreen controls the testing sequence, while an automatic digital timer records elapsed time without relying on operator response. The specimen clamping assembly is precision-machined from high-strength aluminum alloy to maintain stable bore dimensions through repeated clamping cycles and provide corrosion resistance during continuous water exposure.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eA key advantage of this model is its integrated temperature regulation system. The heating and cooling circuit adjusts the supply water to a specified temperature and maintains that set point throughout testing. This minimizes temperature-related variations instead of requiring laboratories to measure fluctuating water temperatures and apply corrections to the results afterward. A dedicated water source tank is also available as a matching component, supplied according to custom configuration requirements.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThe ø80 mm specimen diameter provides an effective test area of approximately 50 cm², roughly 2.5 times larger than the area offered by a 50 mm apparatus. This expanded testing area captures flow behavior across a greater portion of the fabric structure, which is particularly beneficial when evaluating needle-punched nonwovens with varying local densities across a production roll. The floor-standing instrument measures 720 × 700 mm in footprint, stands 1900 mm tall, and weighs 120 kg.\u003c\/span\u003e\u003c\/p\u003e\n\u003ch2\u003e\u003cspan\u003eGeotextile Water Permeability Tester – QualiGTX™ GPT GW Applications\u003c\/span\u003e\u003c\/h2\u003e\n\u003cp\u003e\u003cspan\u003eThe QualiGTX™ GPT GW is designed for laboratories conducting regular cross-plane permeability testing where measurement consistency and reliable results are essential for evaluating compliance with specification limits.\u003c\/span\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eGeotextile Manufacturing QC\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Evaluates water flow capacity across production rolls to verify that manufactured materials consistently meet declared permeability values and specified tolerances across production shifts.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eGeocomposite and Composite Fabric Testing\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Measures cross-plane water flow through multilayer drainage and filtration products using a specimen clamp suitable for thicker materials.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eFilter Compatibility Studies\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Determines fabric flow capacity to support soil-to-geotextile retention evaluations and clogging assessments.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eLandfill and Containment Engineering\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Verifies filtration layer performance in systems installed above leachate collection networks and cap drainage structures.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eDam, Levee, and Canal Works\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Assesses filter fabrics used in hydraulic structures where water flow capacity is critical to long-term seepage control.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eHighway and Railway Drainage\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Evaluates separation and filtration geotextiles used in edge drains, subgrade layers, and drainage blanket systems.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eAccredited Testing Laboratories\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Supports testing requirements that specify controlled water temperature rather than relying on mathematical corrections after measurement.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eGeosynthetics Research Programs\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Investigates changes in water flow capacity resulting from fiber structure, bonding techniques, and water temperature under repeatable testing conditions.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003e\u003cspan\u003eGeotextile Water Permeability Tester – QualiGTX™ GPT GW Key Features\u003c\/span\u003e\u003c\/h2\u003e\n\u003cp\u003e\u003cspan\u003eThe QualiGTX™ GPT GW combines an actively regulated water temperature system with touchscreen controls and a large-area specimen clamping assembly to provide consistent cross-plane permeability measurements.\u003c\/span\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eTemperature-Controlled Water Supply\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Heats or cools the supply water to a selected temperature and maintains that setting throughout the test, helping prevent viscosity variations caused by gradual circuit warming.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eø80 mm Specimen Clamp\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Provides an effective test area of approximately 50 cm², capturing flow across a larger portion of the fabric structure and improving repeatability when testing non-uniform nonwoven materials.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eHigh-Strength Aluminum Alloy Clamp Body\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Maintains stable bore dimensions during repeated specimen clamping and resists corrosion under continuous water exposure.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eLarge Color Touchscreen Control\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Displays test settings, operating status, and measurement results through a centralized interface, supporting consistent operation between technicians.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eAutomatic Digital Timing\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Records elapsed time through automatic clock operation, eliminating operator reaction time from start-and-stop measurements and reducing a major source of error during short, high-flow tests.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eMatched Water Source Tank\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Provides a dedicated water supply component configured to work with the instrument, with tank capacity tailored to laboratory testing throughput.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eCross-Plane Test Geometry\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Measures water movement through the material thickness, the flow direction relevant to filtration and separation performance.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eFloor-Standing Frame\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Integrates the water circuit, temperature regulation system, and specimen testing assembly within a 720 × 700 mm footprint, eliminating the need for a dedicated laboratory bench.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003e\u003cspan\u003eTheory and Method\u003c\/span\u003e\u003c\/h2\u003e\n\u003cp\u003e\u003cspan\u003eCross-plane permeability indicates how easily water passes through the thickness of a geosynthetic material rather than flowing along its surface. The measurement is based on determining the flow rate under a defined hydraulic head across a specified specimen area. Each parameter must remain controlled to produce meaningful and comparable results. The specimen clamp bore determines the test area, with the ø80 mm opening providing approximately 50 cm². This larger area helps represent the overall flow characteristics of the fabric rather than measuring only a localized section beneath a smaller clamp.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eSpecimen area plays an important role in the reliability of permeability measurements. Needle-punched nonwoven geotextiles can exhibit considerable variation at small scales because fiber distribution and needle-punch density are not perfectly uniform across a production roll. When a small specimen area is tested, the measurement captures only a limited portion of this variation. Consequently, repeated specimens may produce a wider spread of results, requiring additional tests to establish a reliable average. A larger clamping area captures more of the fabric structure in each measurement, helping reduce result variability and the number of specimens needed to achieve a statistically defensible mean.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eWater temperature is another major factor affecting measurement accuracy. As water temperature increases, its viscosity decreases, allowing the same geotextile specimen to pass more water at 30 °C than at 15 °C. Standard testing procedures therefore account for temperature by measuring the water temperature and correcting the result to a specified reference value. However, this correction depends on maintaining stable temperature conditions throughout the test. In systems where water circulates through a pump and reservoir, gradual temperature increases can occur over a morning of testing, introducing variations into the measurements.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThe integrated active heating and cooling system addresses this issue by maintaining the water supply at a selected temperature, preventing temperature drift at its source. Automatic digital timing provides an additional accuracy benefit by eliminating human reaction time when recording the start and end of a measurement. Together, controlled water temperature and automatic timing reduce two important sources of measurement variation in cross-plane permeability testing.\u003c\/span\u003e\u003c\/p\u003e\n\u003ch2\u003eGeotextile Water Permeability Tester – QualiGTX™ GPT GW Technical Specifications\u003c\/h2\u003e\n\u003ctable class=\"table table-style-align-center\" align=\"center\" border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"544\"\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eParameter\u003c\/th\u003e\n\u003cth\u003eSpecification\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eTest Orientation\u003c\/td\u003e\n\u003ctd\u003eCross-plane (vertical) water flow\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSpecimen Size\u003c\/td\u003e\n\u003ctd\u003eø80 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSpecimen Clamp Construction\u003c\/td\u003e\n\u003ctd\u003eHigh-strength aluminum alloy\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWater Supply\u003c\/td\u003e\n\u003ctd\u003eTemperature-controlled, with heating and cooling\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWater Source Tank\u003c\/td\u003e\n\u003ctd\u003eSupplied to custom configuration\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eControl System\u003c\/td\u003e\n\u003ctd\u003eLarge color touchscreen\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTiming\u003c\/td\u003e\n\u003ctd\u003eAutomatic, digital display\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDimensions (W × D × H)\u003c\/td\u003e\n\u003ctd\u003e720 × 700 × 1900 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eNet Weight\u003c\/td\u003e\n\u003ctd\u003e120 kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e","brand":"Qualitest USA LC","offers":[{"title":"Default Title","offer_id":53459751272759,"sku":null,"price":100.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0786\/1859\/1543\/files\/geotextile-water-permeability-te.webp?v=1793364660"},{"product_id":"vertical-geosynthetic-water-permeability-tester","title":"Vertical Geosynthetic Water Permeability Tester","description":"\u003ch2\u003e\u003cspan\u003eVertical Geosynthetic Water Permeability Tester – QualiGTX™ GPT V\u003c\/span\u003e\u003c\/h2\u003e\n\u003ch4\u003e\u003cspan\u003eVertical Permeability Testing of Geosynthetics for Water Conservancy Applications\u003c\/span\u003e\u003c\/h4\u003e\n\u003cp\u003e\u003cspan\u003eThe QualiGTX™ GPT V Vertical Geosynthetic Water Permeability Tester measures the rate at which water flows through the thickness of a geosynthetic specimen secured over a fixed 20 cm² test area. Its color touchscreen allows users to configure test parameters, while the digital timer automatically records test duration without requiring continuous operator supervision. This automated operation is particularly useful for extended testing of fine filter fabrics. The instrument accommodates a wide range of geosynthetic materials used in seepage control and drainage applications.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThe tester is particularly valuable in water resources engineering, where the permeability of filter fabrics directly affects the performance of hydraulic structures. Geotextiles installed in embankment dams, levees, canals, and reservoir linings must allow seepage water to pass through at a rate equal to or greater than the flow supplied by the surrounding soil. Vertical permeability measurements help determine whether these requirements are met. The QualiGTX™ GPT V delivers consistent test results, supporting reliable comparisons between different material production lots.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThe specimen clamping assembly is manufactured from high-strength aluminum alloy to maintain dimensional stability during repeated clamping cycles and resist corrosion during prolonged water exposure. Designed as a floor-standing unit, the tester features overall dimensions of 720 × 700 mm, a column height of 1900 mm, and a total weight of 110 kg. Its integrated water circuit and specimen testing cell provide a self-contained testing arrangement while preserving laboratory bench space.\u003c\/span\u003e\u003c\/p\u003e\n\u003ch2\u003e\u003cspan\u003eVertical Geosynthetic Water Permeability Tester – QualiGTX™ GPT V Applications\u003c\/span\u003e\u003c\/h2\u003e\n\u003cp\u003e\u003cspan\u003eThe QualiGTX™ GPT V is designed for hydraulic engineering laboratories and geosynthetic manufacturers supplying materials for water resources infrastructure.\u003c\/span\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eEmbankment Dam Construction\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Evaluates the permeability of filter and drainage fabrics used in dam cores, chimney drains, and toe drains, where effective seepage management is essential to structural safety.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eLevee and Flood Defense Works\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Verifies that filter geotextiles provide sufficient water flow to prevent pressure buildup behind revetments and protective armoring layers.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eCanal and Irrigation Lining\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Tests geotextiles installed beneath or behind canal linings to assess their ability to release trapped seepage water that could otherwise lift or displace the lining system.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eReservoir and Pond Systems\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Determines the flow capacity of filter layers used in underdrainage systems and leak detection installations.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eHydropower Civil Works\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Supports permeability assessment of filter and transition zones incorporated into water-retaining structures.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eGeotextile Manufacturing for Hydraulic Projects\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Provides production lot documentation of water flow capacity against declared values specified in water resources project tenders.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eFilter Criteria Verification\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Establishes the fabric permeability value that engineers compare with soil permeability when evaluating filter compatibility.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eThird-Party and Owner Laboratories\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Supports acceptance testing of delivered geosynthetic materials before their installation in permanent hydraulic structures.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003e\u003cspan\u003eVertical Geosynthetic Water Permeability Tester – QualiGTX™ GPT V Key Features\u003c\/span\u003e\u003c\/h2\u003e\n\u003cp\u003e\u003cspan\u003eThe QualiGTX™ GPT V focuses on two critical factors in reliable vertical permeability testing: effective specimen sealing and accurate measurement of test duration.\u003c\/span\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eMachined Aluminum Alloy Specimen Clamp\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Provides a secure seal around the specimen perimeter, directing water through the fabric rather than allowing flow around its edges. The corrosion-resistant aluminum alloy is suitable for extended exposure to standing water.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eFixed 20 cm² Test Area\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Establishes a precisely defined testing area for permeability calculations, eliminating uncertainty associated with using a nominal opening diameter and its associated tolerance range.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eAutomatic Digital Timing\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Automatically monitors test duration during extended, low-flow measurements of fine filter fabrics, eliminating the need for impractical and potentially inaccurate manual timing.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eColor Touchscreen Control\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Stores test parameters directly on the instrument, allowing consistent testing conditions to be selected and repeated across different operators and material batches.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eCross-Plane Test Geometry\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Measures water flow through the material thickness, the direction relevant to filtration and seepage relief performance.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eBroad Material Coverage\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Supports permeability testing across various geosynthetic materials used for seepage control, drainage, and separation applications.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eFloor-Standing Column Frame\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: Accommodates the specimen cell and water circuit within a 720 × 700 mm footprint, leaving laboratory workbench space available for specimen preparation.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003e\u003cspan\u003eTheory and Method\u003c\/span\u003e\u003c\/h2\u003e\n\u003cp\u003e\u003cspan\u003eFilter design for hydraulic structures depends on comparing the water permeability of the filter fabric with the permeability of the surrounding soil. Water seeping through an embankment or beneath a canal lining must pass through the filter geotextile at a rate equal to or greater than the rate at which the soil supplies it. If the fabric restricts water flow, pressure can accumulate along its upstream surface. This buildup may lift canal linings, weaken embankment cores, and eventually cause soil movement. To prevent these conditions, engineers evaluate fabric permeability against the permeability of the retained soil, applying an appropriate safety margin. Consequently, the measured permeability coefficient serves as an important input for hydraulic filter design and safety assessments.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eA fixed test area of 20 cm² helps maintain accuracy and consistency in permeability calculations. The permeability coefficient is determined using flow volume, elapsed time, hydraulic gradient, and the cross-sectional area through which water passes. Since the test area directly influences the calculation, any uncertainty in its dimensions carries through to the reported coefficient. The precisely machined specimen clamp establishes a consistent testing area, removing this variable from the measurement process. The equivalent circular test opening has an approximate diameter of 50.5 mm.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eSpecimen clamping is equally important because it determines whether the measured water flow accurately represents the flow passing through the geosynthetic material. Water naturally follows the path of least resistance. If the specimen is not properly sealed around its perimeter, water may bypass the fabric through the edges instead of flowing through its structure. This edge leakage produces an artificially elevated permeability result, making the material appear more permeable than it actually is. Such an error can lead to unsafe conclusions during filter design. A rigid, dimensionally stable clamping surface maintains the specimen seal under hydraulic gradient conditions.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eAutomatic digital timing addresses another important challenge in vertical permeability testing. Fine filter fabrics may require extended periods to produce a measurable volume of water because of their low flow rates. Monitoring such lengthy tests manually can be impractical and may introduce timing inaccuracies. The QualiGTX™ GPT V automatically records the test duration, supporting consistent measurements throughout extended testing procedures.\u003c\/span\u003e\u003cspan\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003ch2\u003eVertical Geosynthetic Water Permeability Tester – QualiGTX™ GPT V Technical Specifications\u003c\/h2\u003e\n\u003ctable class=\"table table-style-align-center\" align=\"center\" border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"534\"\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eParameter\u003c\/th\u003e\n\u003cth\u003eSpecification\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eTest Orientation\u003c\/td\u003e\n\u003ctd\u003eCross-plane (vertical) water flow\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSpecimen Test Area\u003c\/td\u003e\n\u003ctd\u003e20 cm² (equivalent to approximately ø50.5 mm)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSpecimen Clamp Construction\u003c\/td\u003e\n\u003ctd\u003eHigh-strength aluminum alloy\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eControl System\u003c\/td\u003e\n\u003ctd\u003eLarge color touchscreen\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTiming\u003c\/td\u003e\n\u003ctd\u003eAutomatic, digital display\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDimensions (W × D × H)\u003c\/td\u003e\n\u003ctd\u003e720 × 700 × 1900 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eNet Weight\u003c\/td\u003e\n\u003ctd\u003e110 kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e","brand":"Qualitest USA LC","offers":[{"title":"Default Title","offer_id":53459752812855,"sku":null,"price":100.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0786\/1859\/1543\/files\/vertical-geosynthetic-water-perm.webp?v=1793364854"}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0786\/1859\/1543\/collections\/geotextile-permeability-testers1.webp?v=1793362897","url":"https:\/\/qualitest.us\/pt\/collections\/geotextile-water-permeability-tester.oembed","provider":"Qualitest USA LC","version":"1.0","type":"link"}