SDHFCS1000 High-Frequency Infrared Carbon and Sulfur Analyzer

The SDHFCS1000 High-Frequency Infrared Carbon and Sulfur Analyzer is designed for fast, accurate, and fully automated determination of total carbon and sulfur in a wide variety of inorganic materials. It is suitable for ferrous and non-ferrous metals, alloy steels, ferroalloys, ores, soils, battery materials, nuclear materials, titanium dioxide, and other metallic and non-metallic samples.

During analysis, the sample is rapidly combusted in a high-frequency induction furnace under a pure oxygen atmosphere. The resulting carbon dioxide and sulfur dioxide are carried into dedicated infrared absorption cells, where their concentrations are measured according to the selective infrared absorption principle. The integrated software automatically controls the entire process, including sample weight acquisition, combustion, signal detection, result calculation, data storage, and report generation.

With automatic switching between high- and low-concentration carbon and sulfur channels, the SDHFCS1000 can analyze unknown samples without requiring the operator to select the expected concentration range in advance. Both high- and low-range results can be processed simultaneously, helping laboratories improve analytical efficiency and reduce the risk of incorrect detector selection.

Key Features

Automatic full-range carbon and sulfur analysis

High- and low-concentration carbon and sulfur detection channels can operate simultaneously. The system automatically evaluates the signals and selects the appropriate result, making it particularly suitable for unknown or blind samples.

Fast high-temperature combustion

The high-frequency induction furnace provides rapid heating and a combustion temperature above 1,600°C for steel samples, ensuring effective sample fusion and complete release of carbon and sulfur. Typical analysis time is adjustable from 25 to 55 seconds.

Wide analytical range and material compatibility

Depending on the detector configuration, the instrument can cover carbon and sulfur concentrations from 0.0001% to 100%. It can be configured for applications ranging from trace-level carbon and sulfur determination to high-concentration analysis.

Stable and reliable infrared detection

Carbon is measured as CO₂ and sulfur as SO₂ using selective infrared absorption. Dedicated gas purification, drying, flow-control, and filtration systems help minimize interference from moisture, background CO₂, dust, and unstable gas flow.

Reduced sulfur adsorption for improved low-sulfur performance

The heated furnace-head design helps prevent moisture accumulation and reduces the adsorption of SO₂ by combustion dust. This allows the instrument to achieve stable sulfur results after startup without requiring lengthy gas-path saturation procedures.

Intelligent dust removal and instrument protection

The system supports automatic dust cleaning and dust-discharge reminders. Intelligent standby and self-protection functions help reduce unnecessary operating load and protect critical components during extended use.

Integrated software and data management

The software provides real-time combustion curves, method management, standard-sample calibration, automatic linearization, statistical calculation, database backup, report printing, and data export in Excel, text, and web-compatible formats. Results can also be transmitted to third-party systems through a serial communication interface.

Enhanced operational safety

High-frequency electromagnetic shielding technology is incorporated to improve operator protection. The software also provides gas-path leak testing, operating-status monitoring, automatic alarms, and emergency-stop control.

Applicable International Standards and Methods
StandardStandard TitleApplicable Samples
ISO 9556Steel and iron — Determination of total carbon content — Infrared absorption method after combustion in an induction furnaceSteel and iron
ISO 4935Steel and iron — Determination of sulfur content — Infrared absorption method after combustion in an induction furnaceSteel and iron
ISO 15350Steel and iron — Determination of total carbon and sulfur content — Infrared absorption method after combustion in an induction furnace (routine method)Steel and iron
ASTM E1019Standard Test Methods for Determination of Carbon, Sulfur, Nitrogen, and Oxygen in Steel, Iron, Nickel, and Cobalt Alloys by Combustion and Inert Gas Fusion TechniquesSteel, iron, nickel, and cobalt alloys
ASTM E1941Standard Test Method for Determination of Carbon in Refractory and Reactive Metals and Their Alloys by Combustion AnalysisRefractory and reactive metals and their alloys
Specifications

Power Supply: 220 V ±5%, 50 Hz

Power Consumption:

  • High-frequency induction furnace: 3.5 kVA
  • Infrared analyzer: 250 VA
  • Electronic balance: 15 VA

High-Frequency Induction Furnace:

  • Maximum output power: 5 kW
  • Anode current, no-load: 0.2–0.3 A
  • Grid current, no-load: 100–150 mA
  • Heating time: Adjustable from 1 to 99 s; typically set to 15–20 s
  • Combustion temperature: >1,600°C for iron and steel samples
  • Maximum heating load: 3 g, including sample and flux
  • Oxygen pressure for cylinder lifting: 0.5 MPa
  • Analysis oxygen pressure in the furnace: 0.06 MPa
  • Maximum permitted furnace pressure: 0.08 MPa, to protect the purification tubes and combustion chamber

Applicable Samples: Carbon steel, high-, medium- and low-alloy steel, ferroalloys, pure metals, and selected non-metallic materials

Measurement Range:

  • Carbon: 0.0001–100%
  • Sulfur: 0.0001–100%

The actual measurement range and applicable sample types depend on the specific instrument configuration.

Precision:

  • Better than the requirements of JJG 395-97
  • Better than the requirements of GB/T 20123-2006 and ISO 15350:2000

Analysis Time: Adjustable from 25 to 55 s

Operating Temperature: 15–30°C

Electronic Balance Readability: 0.0001 g

Dimensions: 680 × 560 × 800 mm

Weight: 85 kg

Application Notes

We are compiling our practical application experience into a growing collection of technical articles that will be published here regularly.

If you have an immediate analytical challenge before then—whether in mining, energy, advanced materials, or PFAS analysis—contact the Sundy Technology Application Laboratory. We provide customized method development, application optimization, and technical support to help you achieve reliable analytical results.

Intuitive Software Ensures Simple Operation

Software Functions

  • Real-time display of carbon and sulfur signal curves
  • Automatic sample-weight acquisition
  • Analysis method management
  • High- and low-range detector selection
  • Automatic high/low concentration result switching
  • Standard reference material database
  • Daily calibration and multipoint system calibration
  • Quadratic, cubic and quartic calibration modes
  • Statistical calculation of mean, standard deviation and RSD
  • Result recalculation using updated calibration coefficients
  • Gas-path leak testing
  • Automatic dust-cleaning and filter-replacement reminders
  • Database backup, repair and compression
  • Report preview, printing and data export
On-site Photos
Videos
Customer Testimonials

We have provided a complete set of Sundy testing solutions, including bomb calorimeter, sulfur analyzer, and thermogravimetric analyzer, to the fuel analysis laboratory of Kavçim Cement, a leading integrated cement plant on Turkey’s Black Sea coast. Sundy’s standardized instrument performance bring outstanding practical value to end users. The upgraded solution significantly simplifies daily operations, lowers manual intervention and maintenance costs, and unifies data consistency for routine fuel analysis.

We are very satisfied with Sundy’s product quality and technical support, and will continue to promote and recommend Sundy analytical instruments for more industrial laboratory projects in Turkey.

Dr. Karahan, POTANTEK

After more than 10 years of continuous cooperation and market verification, we confirm that Sundy’s products, especially its automatic calorimeters and elemental analyzers, have high precise temperature control, accurate testing results, and ultra-low failure rate. All products are fully compliant with international ISO and ASTM standard, completely meeting the testing demands of coal laboratories, power plants, industrial enterprises, universities and scientific research institutions.

We highly recognize Hunan Sundy Science and Technology’s strong production capacity, standardized quality management system, professional technical support team and excellent business credibility. In all our cooperation cases, Sundy has always demonstrated professionalism, reliability and a customer-oriented service attitude.

Dr. Kim, YEONJIN
FAQs

The analyzer combines high-frequency induction combustion with non-dispersive infrared absorption detection. The sample is combusted in a pure oxygen atmosphere, converting carbon into CO₂ and sulfur into SO₂. These gases are carried through the purification system into the corresponding infrared cells, where their concentrations are calculated from their selective infrared absorption.

The system is primarily suitable for carbon steels, high-, medium- and low-alloy steels, stainless steels, ferroalloys, pure metals and selected non-metallic materials. With appropriate sample preparation and flux selection, it may also be used for ores, cement, glass and other difficult-to-combust materials.

The stated analysis range is:

  • Carbon: 0.0001% to 100%
  • Sulfur: 0.0001% to 100%

The actual working range depends on the number and configuration of the installed infrared detection cells.

When both high- and low-range infrared cells are installed, the software can acquire signals from both channels and select the final result according to a predefined switching value. This reduces the risk of selecting an unsuitable detector range when analyzing samples with unknown carbon or sulfur concentrations.

The total analysis time is adjustable from 25 to 55 seconds. The optimum setting depends on the sample matrix, combustion behavior and the time required for the absorption curve to return close to baseline.

For steel samples, the combustion temperature can exceed 1,600°C. The high-frequency induction furnace rapidly heats and melts the sample by generating eddy currents within the conductive material and flux.

The instrument requires bottled oxygen with a purity of at least 99.5%. Oxygen must be sufficiently purified and dried because moisture, CO₂ and hydrocarbons in the oxygen supply can affect the combustion process and infrared detection, particularly sulfur determination.

  • Cylinder-lifting oxygen pressure: approximately 0.5 MPa
  • Furnace analysis oxygen pressure: approximately 0.06 MPa
  • Maximum permitted furnace pressure: 0.08 MPa

Exceeding the maximum pressure may damage the purification tubes or combustion chamber.

The manual indicates a normal oxygen flow of approximately 3 L/min, while the troubleshooting section gives a routine verification range of approximately 2.0–2.8 L/min. The final operating setpoint should therefore follow the value established during instrument commissioning and calibration.

Typical sample quantities are:

  • Iron-based samples: 0.2–0.5 g
  • Maximum iron-based sample mass: 1 g
  • Non-metallic samples: approximately 0.05 g

The total mass of sample plus flux must not exceed the furnace’s maximum heating capacity of 3 g.

Tungsten granules are commonly used because of their high calorific value, good gas permeability and stable combustion characteristics. Pure iron flux can be used for ferroalloys, stainless steels and selected non-metallic materials. For high-chromium steel, high-manganese steel, manganese ore or metallic manganese, a small quantity of molybdenum trioxide may improve sulfur recovery by reducing sulfur adsorption.

  • Tungsten granules: 1.3–1.8 g, maximum 2 g
  • Tungsten–tin alloy: 1.3–1.8 g, maximum 2 g
  • Pure iron flux: 0.3–0.5 g
  • Molybdenum trioxide for selected difficult matrices: approximately 0.05–0.1 g

The exact quantity should be optimized for the sample matrix and expected carbon and sulfur concentrations.

Ceramic crucibles can absorb moisture and may contribute carbon and sulfur blank values. For low-level analysis, the manual recommends heating crucibles at 1,200°C for four hours, followed by cooling and storage in a desiccator. For routine higher-level analysis, crucibles with sufficiently low and stable blanks may be dried at 105°C for two to three hours.

The combustion chamber should normally be cleaned after approximately 40 consecutive analyses. Excessive Fe₂O₃ and WO₃ dust can restrict gas flow, interfere with induction heating and adsorb SO₂, resulting in low or unstable carbon and sulfur values.

The internal high-frequency furnace compartment should generally be cleaned every six to eight months, depending on the installation environment and analysis frequency. Conductive metallic dust must not be allowed to accumulate because it may cause arcing, short circuits or damage to high-voltage components.

The moisture-removal reagent should be replaced when approximately one-third of the indicating desiccant has changed colour. The manual suggests replacing purification reagents at intervals of approximately one to three months, depending on sample throughput and operating conditions. Reagents must also be replaced if they become compacted and restrict gas flow.

The heated furnace head reduces moisture accumulation and minimizes SO₂ adsorption on combustion dust and internal surfaces. This helps prevent low sulfur results after startup and reduces the need for prolonged gas-path saturation before analysis.

The software provides first-stage and second-stage leak-test functions. During the test, the furnace is sealed, oxygen is introduced and the inlet valve is closed automatically. The pressure gauge should then remain stable. Continuous pressure loss indicates a leak, which should be located by checking the furnace section and infrared analyzer section separately.

Before calibration, the instrument should complete at least two blank combustion cycles. The manual states that the displayed carbon and sulfur blank results should generally be below 0.0005%, or below 0.001% for the high-carbon cell. Signal curves should be stable, approximately parallel and free from sharp spikes.

Calibration standards should preferably match the sample matrix—for example, steel standards for steel samples and cast-iron standards for cast-iron samples. Each standard should normally be analyzed two or three times with acceptable repeatability. One-point calibration may be sufficient for routine work, while multi-point calibration is recommended when covering a broad range or performing low-level carbon and sulfur analysis.

Related Products

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