The grading number and characteristics of thermal resistors

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The grading numbers and characteristics of thermal resistors; standardized thermocouples. In China, starting from January 1, 1988, thermocouples and thermal resistors were all manufactured in accordance with IEC international standards, and seven standardized thermocouple types—S, B, E, K, R, J, and T—were designated as the unified standard thermocouple types in China. There are mainly several types such as S, R, B, N, K, E, J, T, etc. Among them, S, R, and B belong to noble metal thermocouples, while N, K, E, J, and T belong to base metal thermocouples. Thermocouple calibration types: S – platinum-rhodium 10; pure platinum. R – platinum-rhodium 13; pure platinum. B – platinum-rhodium 30; platinum-rhodium 6N; nickel-chromium-silicon; nickel-silicon. K – nickel-chromium; nickel-silicon E. Nickel-chromium; copper-nickel. J – iron; copper-nickel. T – pure copper; copper-nickel. Characteristics of each calibration type: The S calibration type has excellent oxidation resistance and the highest accuracy, making it commonly used as a standard thermocouple. R grading: It has basically the same properties as the S grading; the only difference is that its electromotive force is about 15% higher than that of S. B grading: It can be used under oxidizing conditions as well as for a short period of time in vacuum conditions; however, its electromotive force is very low at room temperature. N grading number: It can withstand low temperatures and radiation, has a relatively stable thermoelectromotive force, and also possesses strong oxidation resistance. K rating: It has strong antioxidant properties, allowing it to be used under oxidative conditions; its range of applications is very wide. E scale rating: Extremely high sensitivity, allowing for continuous use in oxidative atmospheres. J indexing number: It can be used in both oxidizing and reducing atmospheres, and it also has good corrosion resistance. T classification: It belongs to the category of thermocouples made from base metals with the highest precision.