Apr 19, 2021
How To Distinguish Thermocouple Models?
Recently, there are often customers inquiring about thermocouple model problems. The following editor summarizes:
Commonly used thermocouples can be divided into two categories: standard thermocouples and non-standard thermocouples. The called standard thermocouple refers to a thermocouple whose national standard specifies the relationship between its thermoelectric potential and temperature, its allowable error, and has a unified standard graduation table. It has a matching display instrument for selection. Non-standardized thermocouples are inferior to standardized thermocouples in the scope of use or order of magnitude, and there is generally no unified indexing table, which is mainly used for measurement in some special occasions.
The indexing numbers of thermocouples are mainly S, R, B, N, K, E, J, T and so on. Among them, S, R, and B belong to precious metal thermocouples, and N, K, E, J, and T belong to low-cost metal thermocouples.
The following is an explanation of the thermocouple indexing number:
S platinum rhodium 10 pure platinum
R platinum rhodium 13 pure platinum
B platinum rhodium 30 platinum rhodium 6
K Nickel Chromium Nickel Silicon
T pure copper copper nickel
J iron copper nickel
N Ni-Cr-Si Ni-Si
E nickel-chromium copper-nickel
(S-type thermocouple) platinum rhodium 10-platinum thermocouple
The platinum rhodium 10-platinum thermocouple (S-type thermocouple) is a precious metal thermocouple. The diameter of the couple wire is specified as 0.5mm, and the allowable deviation is -0.015mm. The nominal chemical composition of the positive electrode (SP) is platinum-rhodium alloy, which contains 10% rhodium, 90% platinum, and the negative electrode (SN) is pure platinum. Commonly known as single platinum rhodium thermocouple. The long-term maximum use temperature of this thermocouple is 1300℃, and the short-term maximum use temperature is 1600℃.
