Automatic Glow Wire Tester (GWIT and GWFI) - QualiFlame™ GWT-A
Computer-Controlled Glow Wire Test Apparatus for Ignition Temperature and Flammability Index Testing
The QualiFlame™ GWT-A Automatic Glow Wire Tester is designed to determine the Glow-Wire Ignition Temperature (GWIT) and Glow-Wire Flammability Index (GWFI) of solid insulating materials, engineering plastics, and finished electrical components. It simulates the thermal stress that can occur when an overloaded resistor or malfunctioning heating element exposes polymer materials to elevated temperatures under fault conditions.
The system heats a nickel-chromium glow wire loop to a selectable temperature from 550°C to 1050°C, maintains the selected temperature for one minute, and then brings the glow wire into contact with the test specimen under controlled force. This controlled procedure supports consistent evaluation of ignition and flammability characteristics.
Automated Testing and Data Analysis
A built-in microcomputer controls the test sequence and generates temperature-time and current-time curves during testing. The QualiFlame™ GWT-A automatically records key test parameters, including ignition time, flame extinction time, and ignition of the tissue layer caused by flaming droplets. Automated timing helps reduce measurement inconsistencies associated with manual stopwatch-based glow wire testing.
Test results and curves can be stored, reviewed, and exported through a single operating interface. The integrated test chamber features a cast construction and extraction system that helps remove combustion products from the testing area during operation.
Applications
The QualiFlame™ GWT-A Glow Wire Test Apparatus is suitable for applications across:
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Electrical and electronic component testing
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Electrical appliance manufacturing
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Engineering plastic evaluation
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New-energy material development
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Polymer material screening
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Finished product qualification
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Third-party testing and certification laboratories
Optional features such as robotic specimen handling, barcode traceability, and cloud connectivity can support automated batch testing and laboratory data management.
Qualitest provides the GWT-A Automatic Glow Wire Tester with calibration accessories and application support for testing laboratories across North America.
Automatic Glow Wire Tester (GWIT and GWFI) - QualiFlame™ GWT-A Applications
The QualiFlame™ GWT-A Automatic Glow Wire Tester supports laboratories evaluating whether materials and electrical components can resist ignition when exposed to localized overheating. Its controlled temperature range, applied force, and test procedure make it suitable for glow-wire testing programs focused on material flammability and ignition performance.
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Electrical and Electronic Components: Evaluates connectors, switches, relay housings, terminal blocks, and printed circuit board substrates positioned near current-carrying components.
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Household Appliance Manufacturing: Tests enclosures, control panels, and internal structural components against glow-wire requirements specified in appliance safety programs.
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Engineering Plastics and Compounding: Supports the evaluation of flame-retardant formulations during material development, allowing comparison of additive systems based on GWFI and GWIT performance.
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Wire and Cable Insulation: Evaluates insulation and jacketing compounds for resistance to ignition caused by contact with an adjacent heated or glowing element.
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New Energy and Battery Materials: Screens separator films, battery module housings, and busbar insulation used in battery packs and energy storage systems.
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Composite and Laminate Materials: Tests glass-reinforced laminates, structural composites, and coated substrates where resin composition influences ignition and flammability characteristics.
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Automotive Electrical Systems: Evaluates fuse boxes, wiring harness supports, and electronic housings exposed to localized heat within automotive electrical systems.
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Certification and Third-Party Laboratories: Generates traceable GWIT and GWFI test records to support compliance documentation, type approval, and customer audit requirements.
Standards
The QualiFlame™ GWT-A Glow Wire Tester is designed for glow-wire testing procedures referenced by product safety programs for insulating materials and electrical products. Controlled test parameters, including glow-wire geometry, applied force, penetration depth, and calibration procedures, support testing in accordance with applicable standards.
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IEC 60695-2-10 - Fire Hazard Testing, Part 2-10: Glowing/Hot-Wire Based Test Methods, Glow-Wire Apparatus and Common Test Procedure
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IEC 60695-2-13 - Fire Hazard Testing, Part 2-13: Glowing/Hot-Wire Based Test Methods, Glow-Wire Ignition Temperature (GWIT) Test Method for Materials
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UL 746A - Standard for Polymeric Materials, Short Term Property Evaluations
Automatic Glow Wire Tester (GWIT and GWFI) - QualiFlame™ GWT-A Key Features
The QualiFlame™ GWT-A Automatic Glow Wire Tester combines a robust, sealed test chamber with an advanced computer-controlled system for precise temperature regulation, test timing, data acquisition, and reporting. Its modular construction and configurable software support reliable glow-wire testing across a range of laboratory applications.
Key Features
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Integral Cast Test Chamber: A corrosion-resistant, coated, single-piece enclosure houses the glow-wire loop, carriage, and specimen in fixed alignment. This construction helps maintain consistent test geometry during repeated high-temperature testing.
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Layered Modular Design: Separate levels accommodate the control system, test assembly, and flue-gas extraction components. This layout provides convenient service access while minimizing disruption to the calibrated testing area.
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Concealed Check-Valve Extraction System: An electric check-valve exhaust system provides adjustable airflow from 0 to 2 m³/min at a noise level of 55 dB or less. Anti-backflow efficiency exceeding 99% helps prevent smoke from returning to the laboratory.
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x86 Computer-Controlled Platform: A 2.6 GHz processor, 8 GB RAM, and a 256 GB SSD, expandable to 2 TB, support local operation of the testing software and storage of extended test campaigns.
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Dual Gigabit Ethernet Connectivity: Two Ethernet ports with transmission speeds of up to 1000 Mbps and IEEE 1588 Precision Time Protocol support facilitate laboratory network integration and synchronized data management.
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Real-Time Curve Acquisition: Temperature-time and current-time curves are displayed as testing progresses. Stored curves remain accessible for online analysis and raw-data review.
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Configurable Test Reporting: Users can edit test schemes, create customized report templates, and save, export, or print test results. The system supports storage of 100 or more test records.
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Multi-Point Software Calibration: Linear correction across multiple temperature and current measurement points helps improve measurement accuracy without requiring hardware adjustments.
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7 mm Penetration Depth Control: A dedicated penetration limiter supports testing of both flat and curved specimens while maintaining consistent glow-wire contact depth across different sample shapes.
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ASTM B115 Calibration Probe: An oxygen-free copper sensor probe supports stable thermal response during instrument verification and calibration checks.
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Adjustable Test Timing: Software controls allow adjustment of the heating period, specimen contact duration, and data-recording windows, supporting a variety of glow-wire testing procedures.
Theory and Method
Glow-wire testing simulates a localized overheating event in which an internal electrical component reaches high temperatures and the surrounding polymer material is exposed to a glowing heat source. The QualiFlame™ GWT-A reproduces this condition using a U-shaped nickel-chromium loop containing approximately 77% nickel and 20% chromium, with a 4.00 mm diameter and current capacity of up to 170 A.
Resistive heating brings the glow wire to the required test temperature. A Type K sheathed thermocouple positioned at the wire tip provides temperature feedback for closed-loop control, maintaining the selected temperature within ±2°C. Silver foil calibration provides a physical temperature reference for verifying thermocouple positioning, with pure silver melting at 961.8°C.
After the glow wire reaches the selected temperature and remains stable for one minute, the specimen carriage moves horizontally at 18 ±3 mm/s until the specimen contacts the glow wire under a force of 0.95 N. A mechanical penetration stop limits contact depth to 7.0 mm, helping maintain consistent test geometry across different specimen materials and shapes.
During contact, heat transfers from the glow wire into the specimen surface. As the polymer reaches its decomposition temperature, volatile products are released and mix with surrounding air. Depending on the material's thermal and flammability characteristics, these gases may ignite or disperse without sustained combustion.
The instrument automatically records the ignition time and, following the standard 30-second contact period, measures flame extinction time. It also monitors the tissue layer beneath the specimen for ignition caused by flaming droplets.
GWFI and GWIT Determination
The two primary glow-wire indices evaluate different aspects of material behavior:
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Glow-Wire Flammability Index (GWFI): Determines the highest test temperature at which the specimen either does not ignite or self-extinguishes within 30 seconds after glow-wire removal, without burning through the specimen or igniting the tissue layer underneath.
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Glow-Wire Ignition Temperature (GWIT): Determines the highest temperature at which three specimens do not ignite. The reported GWIT is then 25 K above the highest temperature at which ignition does not occur, or 30 K above that temperature when the value exceeds 900°C.
Automated current regulation, temperature control, timing, and test-curve acquisition help improve repeatability between operators and across testing cycles. The resulting data provides a consistent basis for evaluating the ignition and flammability behavior of polymeric insulating materials and electrical components.
Automatic Glow Wire Tester (GWIT and GWFI) - QualiFlame™ GWT-A Technical Specifications
| Parameter |
Specification |
| Model |
QualiFlame™ GWT-A |
| Test Temperature |
Room temperature to 1050°C, ±2°C, continuously adjustable |
| Hot Period Duration |
0 to 9999.9 s, ±0.1 s, continuously adjustable |
| Ignition Time Recording |
0 to 9999.9 s, ±0.1 s, circuit-controlled |
| Fall Time Recording |
0 to 9999.9 s, ±0.1 s circuit-controlled |
| Penetration (Browning) Depth |
7.0 mm ±0.5 mm |
| Test Advance Speed |
18 ±3 mm/s |
| Applied Force |
0.95 ±0.1 N |
| Glow Wire Material |
Nickel-chromium alloy (Ni 77%, Cr 20%), Ø4.00 mm ±0.07 mm |
| Glow Wire Shape |
U-shaped loop, horizontal and stationary |
| Thermocouple |
Type K, sheathed (armored), Ø1 mm |
| Calibration Method |
Silver foil, 960°C ±10°C |
| Heating Current |
0 to 170 A, continuously adjustable |
| Test Chamber Volume |
Greater than 0.5 m³ |
| Smoke Extraction |
Ø100 mm duct (standard); adjustable air velocity 0 to 2 m/s (optional) |
| Control Platform |
x86 architecture, 2.6 GHz, 8 GB RAM, 256 GB SSD (expandable to 2 TB) |
| Data Interface |
Dual gigabit Ethernet, up to 1000 Mbps, IEEE 1588 support |
| Test Record Storage |
100 or more test datasets |
| Overall Dimensions |
1340 mm (W) × 720 mm (D) × 1060 mm (H) |
| Weight |
Approximately 150 kg |
| Recommended Bench Size |
1500 mm (L) × 1000 mm (W) × 700 mm (H) |
| Wall Clearance |
200 mm minimum recommended |
| Voltage |
220 V ±10%, 50 Hz, 500 VA (110V is also available) |
Listed values are standard product specifications. Customized configurations follow the contract and technical agreement.
Optional Configurations
| Item |
Description |
| High-Definition Process Recording |
1080p at 60 fps low-light HDR camera that records and stores the full test sequence, with real-time retrieval for editing and archiving |
| Voice Interaction System |
Customizable voice announcement module that reports test status aloud during operation |
| IoT Cloud Platform |
4G/5G network module for remote monitoring, program download, status tracking, alarm notification, and parameter adjustment, with Modbus and TCP integration into MES and other plant systems |
| Automated Testing System |
Six-axis robotic arm with ±0.025 mm repeat positioning that handles sample pickup, delivery, placement, clamping, testing, data recording, and waste retrieval; one arm can serve two testers over a bus network |
| Sample Traceability System |
Barcode scanning that captures material, batch, and test scheme data and links the record from sample submission through testing to report generation |
| Upgraded Exhaust System |
Constant-speed fan with adjustable air velocity for laboratories that need higher extraction capacity |
