How do Carbon Sulfur Analyzers work?
A carbon sulfur analyzer places a weighed sample of 0.05–1 g in a ceramic crucible, adds tungsten or iron and tin accelerators, and heats it in a high-frequency induction furnace or a resistance tube furnace in flowing oxygen. The accelerators couple with the induction field, melting the sample at 1500–2000 °C and oxidizing carbon to CO2 and sulfur to SO2. Dust is removed by a filter, and the gas passes through infrared absorption cells tuned to about 4.26 µm for CO2 and 7.35 µm for SO2. Absorbance follows the Beer–Lambert relationship, and integrated peak area is converted to mass percent using calibration with certified steel or ore standards. High-carbon and low-carbon channels with different path lengths extend dynamic range from ppm levels to several percent.
Which Carbon Sulfur Analyzers variants are available?
- High-Frequency Infrared Carbon Sulfur Analyzer — A high-frequency infrared carbon sulfur analyzer burns metal samples in an induction furnace and measures CO2 and SO2 by infrared cells.
- Resistance Furnace Carbon Sulfur Analyzer — A resistance furnace carbon sulfur analyzer heats samples in a tube furnace at up to 1350 °C and measures CO2 and SO2 by infrared.
- Dual-Furnace Carbon Sulfur Analyzer — A dual-furnace carbon sulfur analyzer combines an induction furnace and a resistance furnace in one system.
- Low-Range Carbon Sulfur Analyzer for High-Purity Metals — A low-range carbon sulfur analyzer is optimized for ppm-level carbon and sulfur in high-purity metals such as titanium, copper, nickel, and electronic-grade alloys.
- Automated Carbon Sulfur Analyzer with Autosampler — An automated carbon sulfur analyzer adds a crucible autosampler and robotic loading to an induction furnace system.
How do I choose the right variant?
Choose the furnace type first. High-frequency induction furnaces reach the temperatures needed for refractory metals, alloys, and ferroalloys, and give fast 30–60 second analyses. Resistance tube furnaces suit ores, cement, coal, and minerals, which do not couple with induction, and provide better stability for sulfur in non-metals. Next define the range: ppm-level carbon in ultra-low-carbon steel or titanium requires low-range cells, low blank, and careful crucible handling, while cast iron needs a high-range channel. Consider throughput through autosamplers and automatic cleaning, and check accessory needs such as crucible ovens, balances, and gas purifiers. Confirm that vendor documentation references ASTM E1019 or GB/T 20123, and ask for repeatability on certified reference materials representing your actual grades.
Where are Carbon Sulfur Analyzers used?
Carbon Sulfur Analyzers are specified in steel and cast iron composition control, ferroalloy and metal powder testing, ore, cement, and mineral carbon-sulfur content, ceramic and refractory material analysis and battery cathode and graphite materials.
Which standards and certifications apply?
Work with Carbon Sulfur Analyzers is commonly governed by ASTM E1019, ASTM E1941, ISO 15350, ISO 9556, GB/T 20123, GB/T 223.69 and IEC 61010-1. Instrument certifications such as CE marking are confirmed per configuration and never assumed.
What are the key considerations before purchase?
Crucibles must be pre-ignited at about 1000–1100 °C for one to two hours to reduce carbon blanks, and stored in a desiccator. Oxygen of at least 99.5% purity and a regulated supply of 2–3 bar are standard, with compressed air or nitrogen for pneumatic functions. The dust filter, anhydrone or magnesium perchlorate scrubbers, and furnace chamber need cleaning after a defined number of analyses, typically 30–100 for high-dust steels. Calibrate with certified reference materials bracketing the working range and run drift checks every few hours. Extraction of exhaust gases is required because SO2 is released during combustion. Induction furnaces emit radio-frequency energy and should be installed according to manufacturer guidance and IEC 61010-1 safety requirements.
