Carbon and Sulfur Analyzer

Carbon & Sulfur Analyzer systems provide accurate measurement of total carbon and sulfur in solid materials, helping laboratories verify material chemistry for production release, incoming inspection, quality control, and R&D. The QualiCSA™ 5 and QualiCSA™ 3 use combustion and infrared (IR) detection to measure carbon as CO₂ and sulfur as SO₂. Integrated gas conditioning supports consistent and reliable analysis across a wide range of material matrices.

General Description of Carbon & Sulfur Analyzer

A Carbon & Sulfur Analyzer combusts a solid sample in an oxygen-rich environment, converts the combustion products into measurable gases, and uses infrared detection cells to quantify carbon and sulfur concentrations.

The QualiCSA™ 5 Carbon & Sulfur Analyzer features high-frequency induction combustion with multi-channel IR detection. Its gas path incorporates dust filtration, moisture removal, catalytic conversion, and stabilized flow control to support dependable analytical performance across different sample types.

The QualiCSA™ 3 Carbon & Sulfur Analyzer uses high-frequency heating and infrared detection for rapid, simultaneous carbon and sulfur analysis. It is suitable for testing metals, alloys, ores, and other related materials in laboratory and quality control environments.

Applications

Carbon & Sulfur Analyzers are used across metals, mining, materials research, and industrial quality control laboratories for reliable carbon and sulfur measurement.

Steel, Cast Iron, and Alloy Quality Control
- Supports grade verification, melt control, and final release testing where carbon and sulfur limits can influence weldability and downstream material performance.
Non-Ferrous Metals and Superalloys
- Enables carbon and sulfur measurement at low concentrations to help maintain consistent material composition and processing characteristics across production lots.
Cemented Carbides and New Energy Materials
- Provides carbon analysis for composition control and material development, supporting both research activities and routine quality control.
Ores, Soil, Sand, Glass, and Mineral Samples
- Supports analysis workflows for powder-based and moisture-bearing materials commonly tested in mining, geology, mineral processing, and materials laboratories.

Operating Principle: High-Frequency Combustion and IR Detection

The QualiCSA™ 5 and QualiCSA™ 3 Carbon & Sulfur Analyzers use high-frequency combustion and infrared (IR) detection for rapid carbon and sulfur analysis. The analytical process converts carbon and sulfur in a solid sample into measurable gases and determines their concentrations through infrared absorption.

Depending on the sample type and analyzer configuration, analysis can typically be completed within approximately 40 to 60 seconds through three primary stages: high-temperature combustion, gas conditioning and purification, and infrared detection.

High-Temperature Induction Combustion

The analysis begins by placing a solid sample into a ceramic crucible within an oxygen-rich combustion chamber. The sample may include steel, cast iron, alloys, minerals, or other suitable solid materials.

High-frequency induction energy heats and combusts the sample, converting carbon into carbon dioxide (CO₂) and sulfur into sulfur dioxide (SO₂). The QualiCSA™ 5 uses a 13.56 MHz induction frequency, while the QualiCSA™ 3 operates at 18 MHz.

For specialized coal and mineral applications, the QualiCSA™ 3G can be configured with an adjustable tubular resistance furnace, providing an alternative heating method for specific sample requirements.

Gas Conditioning and Purification

Following combustion, the generated gases pass through a conditioning and purification system before entering the infrared detection cells. The gas path helps remove dust and moisture while conditioning the combustion gases for stable measurement.

Automatic dust removal and moisture control help maintain a consistent gas stream and reduce potential interference during analysis. These processes are particularly useful when analyzing powdery, mineral, or moisture-bearing materials.

Infrared (IR) Detection and Absorption

After conditioning, the combustion gases enter infrared measurement cells. Carbon dioxide (CO₂) and sulfur dioxide (SO₂) absorb infrared radiation at characteristic wavelengths, allowing the analyzer to determine the corresponding carbon and sulfur concentrations.

Solid-state pyroelectric detectors and narrow-band optical filters provide selective measurement of the target gases while helping minimize interference from other components in the gas stream.

Calibration Strategy and High-Precision Performance

High-frequency combustion with IR detection is a comparative analytical method that relies on calibration against certified reference materials. Proper calibration establishes the relationship between detector response and known carbon and sulfur concentrations, supporting accurate quantitative analysis.

A typical calibration procedure can include measurement of a blank crucible followed by certified reference materials. Blank correction helps account for background signals and can improve measurement performance, particularly when analyzing low concentrations of carbon and sulfur.

The QualiCSA™ 5 provides sulfur detection capability down to 0.6 ppm, with an instrument sensitivity of 0.01 ppm under specified conditions. The QualiCSA™ 3 provides a lower detection limit of 1 ppm.

Calibration functions are designed to support linear calibration curves and consistent recovery of reference materials, helping laboratories maintain reliable analytical performance during routine testing.

Gas Flow Stabilization and Carryover Mitigation

Stable gas flow is important for reliable carbon and sulfur analysis. The QualiCSA™ analyzers use controlled gas paths and oxygen flow management to transport combustion products from the combustion chamber through the conditioning system and into the IR detection cells.

A direct gas path helps reduce the potential for residue accumulation and carryover between measurements. Proper gas conditioning also supports consistent detector response during successive analyses.

For applications involving geological and mineral samples, configurations such as the QualiCSA™ 5M provide enhanced moisture removal and automatic dust management to address the characteristics of powdery and moisture-bearing materials.

Together, controlled combustion, gas purification, moisture management, and stable gas flow support repeatable carbon and sulfur measurements across a broad range of laboratory samples.

Why Choose Qualitest for Your Carbon & Sulfur Analyzer?

Qualitest Carbon & Sulfur Analyzer systems are designed for production QC and R&D laboratories that require fast analysis, repeatable measurements, and efficient daily operation.

The QualiCSA™ 5 combines high-frequency induction combustion, dust filtration, moisture removal, stabilized gas flow, and multi-channel IR detection to support consistent results across a variety of sample types.

The instrument software is designed to simplify routine testing and laboratory workflows. The interface provides instrument status and analytical trends, guided operating prompts, calibration functions, and configurable access control options. This combination of hardware and software features supports efficient carbon and sulfur analysis for demanding laboratory applications.