A common type of thermocouple

Commonly used thermocouple could be divided into two types: standard thermocouple and non-standard thermocouple. Standard thermocouple refers to the national standard specifies its thermoelectric potential and the relationship between temperature, permissible error, and a unified standard score table of thermocouple, it has with matching display instrument to choose from. Non-standard thermocouple or on the order of magnitude less than the range using standardized thermocouple, generally no unified indexing table, mainly used for the measurement of some special occasions. Standardized thermocouple China since January 1, 1988, thermocouple and thermal resistance were manufactured according to IEC international standard, and specify the S, B, E, K, R, J, T seven standardization thermocouple type thermocouple for China unified design.

thermocouple degree, heat the positive negative electrode materials S platinum rhodium - 10 Pure platinum, R platinum rhodium - 13 Pure platinum and platinum rhodium - 30 B Nickel chromium nickel silicon platinum rhodium, 6 K, T, pure copper, copper nickel J iron copper and nickel, N nickel chrome silicon, silicon nickel E nickel chromium copper nickel, in theory, any two different conductors ( Or a semiconductor) Can be made into thermocouple, but as a practical temperature measurement components, be * * to its manifold. In order to guarantee the reliability of engineering, as well as the measuring accuracy of enough, not all materials can form a thermocouple, general

thermocouple of electrode materials, basic to * * :

1, within the scope of the temperature measurement, thermoelectric properties of stability, not change with time, there is plenty of physical and chemical stability, less susceptible to corrosion and oxidation;

2, small temperature coefficient of resistance, high electrical conductivity, specific heat;

3, large temperature of thermoelectric ShiYao, and between thermoelectric potential and temperature is linear or close to linear single valued function relation;

4, material replication is good, high mechanical strength, simple manufacturing process, the price is cheap.