This document warns users that they should have formal laboratory work experience. As not all safety issues are covered, users need to take appropriate safety and health measures to ensure compliance with national regulations. The document describes the method for the determination of carbon content in ferromanganese, manganese silicon alloy, ferromanganese nitride and metal manganese by infrared absorption method, gas volumetric method, weight method and Coulometry. It is suitable for the determination of carbon content in ferromanganese, manganese silicon alloy, ferromanganese nitride and metal manganese. The measurement range of method 1 is 0.010%~ 10.00%; method 2 is 0.40%~ 5.00%; method 3 is 4.00%~ 8.00% (suitable for high carbon ferromanganese); method 4 is 0.010%~ 0.40% (only suitable for metal manganese). The document refers to a number of normative documents, including the taking and preparation of samples for chemical analysis of ferroalloys, Precision of Measuring methods and results, and numerical revision rules. The required terms and definitions are not defined in the document. Method 1 uses infrared absorption method. The principle is to convert carbon into carbon dioxide through high-frequency induction furnace combustion, and then the measurement Absorption of carbon dioxide in cuvette to infrared rays of specific wavelengths, and the carbon content is obtained by the ratio of absorption value to carbon dioxide flowing through.