Carbon and sulfur analyzers are used to detect and analyze the percentage content of carbon and sulfur in materials such as metals, ores, coke, and cement. Currently, there are many models and types of carbon and sulfur analyzers on the market. Different types of carbon and sulfur analyzers have different design principles and operating methods. Users should choose the appropriate carbon and sulfur analyzer based on their needs and actual conditions. This article briefly introduces the principles, use, and model selection of carbon and sulfur analyzers. Generally, carbon and sulfur analyzers adopt microcomputer-controlled automatic workflow and data processing, have strong anti-interference capabilities, and stable and reliable performance. For example, gas volumetric method and liquid absorption method are used for carbon determination, and the absorbent can be used for a long time without frequent replacement. Iodometric method is used for sulfur determination, and high-precision photosensitive elements are used to control automatic titration, ensuring a constant endpoint. It boasts advantages such as automatic switching between high-carbon, low-carbon, high-sulfur, and low-sulfur modes, switching between resistance furnace and high-frequency furnace modes, high sensitivity, stable performance, accurate and reliable analytical results, wide measurement range, and broad applications. It can rapidly analyze the carbon and sulfur content in solid and fluid materials such as steel, cast iron, copper, alloys, ores, cement, ceramics, carbon compounds, minerals, coal, coke, petroleum, ash, catalysts, lime, gypsum, soil, rubber, leaves, soot, garbage, sand, and glass. Working principle: After purification, the carrier gas (oxygen) is introduced into the combustion furnace (resistance furnace or high-frequency furnace). The sample is oxidized by oxygen at high temperature in the combustion furnace, causing the carbon and sulfur in the sample to be oxidized into CO2, CO, and SO2. The generated oxides are then purified by dust removal and water removal devices and carried by oxygen into the sulfur detection cell for sulfur determination. Subsequently, a mixed gas containing CO2, CO, SO2, and O2 enters the heated catalyst furnace, where it undergoes catalytic conversion: CO→CO2 and SO2→SO3. This mixed gas then enters the desulfurization reagent tube and is introduced into the carbon detection cell to determine the carbon content. Residual gas is discharged outdoors by the analyzer. Simultaneously, the carbon and sulfur analysis results are displayed as %C and %S on the main unit's LCD screen and the connected computer monitor, and stored in the computer for easy retrieval. They can also be printed via a connected printer. When purchasing carbon and sulfur analyzers, users should generally pay attention to the following three aspects: First, the instrument should be selected based on the company's product needs. The purpose of purchasing the instrument is to ensure the quality control of the company's products, so the instrument's adaptability to the company's products is crucial. For example, pre-furnace testing should be as fast as possible, incoming material inspection should ideally be able to print test reports, and finished product inspection should consider the instrument's authority. For manufacturers of single products such as steel and wire rope, the requirements for specialized instruments can be appropriately reduced. However, companies that produce copper alloys, aluminum alloys, or stainless steel should pay particular attention to the specialization of their instruments. Generally speaking, more specialized instruments provide more accurate and convenient testing. Secondly, instrument needs should be categorized into large, medium, and small based on the company's size. Large companies can typically configure a high-frequency infrared carbon-sulfur analyzer and a direct-reading spectrometer, with the laboratory cost controlled to around 1 million yuan. Companies with limited resources can consider configuring a non-aqueous carbon-sulfur analyzer, a 721-type spectrophotometer, and a 328AB-type analytical balance to build a laboratory; the total cost for a 15-square-meter laboratory is less than 10,000 yuan. Most domestic companies in my country, which need to meet both quality control requirements and timely and accurate testing, can configure a highly automated gas volumetric carbon-sulfur high-speed analyzer and a microcomputer-based elemental analyzer, with the entire laboratory costing between 15,000 and 18,000 yuan. For non-ferrous metal manufacturers who do not need to determine the carbon and sulfur content, purchasing a microcomputer multi-element analyzer and a sample balance, along with all the chemical glassware and a complete set of chemical reagents, would cost around ten thousand yuan. Thirdly, in terms of instrument quality, price, and service, the primary consideration should be the service capabilities of the instrument supplier. Currently, high-end instruments, such as large direct-reading spectrometers, are generally of higher quality than domestic products from well-known foreign manufacturers, and their prices are not comparable. Domestic mid-range instruments are largely similar in quality and performance, with only slight differences in functionality.