There are various types of carbon and sulfur analyzers, and the principles of chemical analysis are also different. The scope of application is also different, and the prices vary greatly. Now, the several commonly used analytical methods for carbon and sulfur analyzers are summarized as follows:
1. Infrared absorption method (infrared carbon sulfur analyzer):
The carbon and sulfur in the sample are heated at high temperatures under oxygen rich conditions and oxidized into carbon dioxide and sulfur dioxide gases.
After processing, the gas enters the corresponding absorption pool to absorb the corresponding infrared radiation, which is then forwarded by the detector into a signal and processed by a computer to output the result.
This method has the characteristics of accuracy, speed, and high sensitivity, and is used for both high and low carbon and sulfur content;
The infrared carbon and sulfur analyzer using this method has a high degree of automation and a relatively high price, making it suitable for situations with high analysis accuracy requirements.
2. Conductivity method (conductivity carbon sulfur meter):
This is a method of measuring and analyzing carbon and sulfur content based on changes in conductivity. The mixed gas produced by high-temperature combustion of the tested sample;
After being absorbed by the conductivity cell, the resistivity (reciprocal of conductivity) changes, thereby determining the content of carbon and sulfur. Its characteristics are accuracy, speed, and sensitivity. Commonly used for low-carbon and low sulfur measurements.
3. Capacity method (gas volume carbon sulfur meter):
The commonly used methods for measuring carbon are gas volumetric method, while for measuring sulfur are iodometric method and acid-base titration method.
Especially the gas volumetric method for measuring carbon and iodometric sulfur is both fast and accurate;
It is a commonly used method for the joint determination of carbon and sulfur in China. The accuracy of the carbon and sulfur analyzer using this method has a lower limit of 0.050% for carbon content and 0.005% for sulfur content, which can meet the needs of most occasions.
4. Titration method (burette):
The non-aqueous titrator is used to determine carbon and sulfur elements in steel using acid-base titration method.
Matched with electric arc combustion furnaces, suitable for general laboratory and furnace front testing.
5. Gravimetric method (carbon sulfur combined analyzer):
Alkaline asbestos is commonly used to absorb carbon dioxide, and the carbon content is calculated from the increment.
The determination of sulfur is commonly done by wet method, where the sample is decomposed and oxidized by acid, transforming into sulfate;
Then, barium chloride is added to the hydrochloric acid medium to generate barium sulfate. After precipitation, filtration, washing, and burning, the sulfur content is calculated by weighing *.
The disadvantage of the weight method is its slow analysis speed, so it cannot be used for on-site carbon and sulfur analysis in enterprises. The advantage is that it has high accuracy;
It is still recommended as a standard method both domestically and internationally, and is suitable for standard laboratories and research institutions.
6. The determination of carbon and sulfur content in metals, as well as ICP, direct reading spectroscopy, X-ray fluorescence, mass spectrometry, chromatography, activation analysis, etc., each have their own advantages and applicability.
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