The Principle of Temperature Measurement Using T-type Thermoelectric Couple

Thermocouple is one of the most commonly used temperature detection elements in the industry. T-type thermocouple is a type of thermocouple, and its application range is also very wide. Is the temperature measurement principle of T-type thermocouple the same as that of ordinary electric thermocouple? What is the difference? The following editor will introduce the temperature measurement principle of T-type thermocouple in detail.

T-type thermocouple is also called copper-constantan thermocouple (copper/nickel-copper thermocouple, graduation number T, measurement range -200~+350℃), which is also a kind of low-cost metal thermocouple for measuring high temperature. Its positive electrode (TP) is pure copper, and its negative electrode (TN) is copper-nickel alloy, often called constantan. It is compatible with constantan EN of nickel-chromium-constantan, but not with constantan JN of iron-constantan. Although they are all called constantan, the measurement temperature range of copper-copper-nickel thermocouple is -200~350℃.

T-type thermocouples have the advantages of good linearity, large thermoelectric potential, high sensitivity, good temperature approximation linearity and reproducibility, fast heat transfer, good stability and uniformity, and low price. They are especially used in the temperature range of -200~0℃, with better stability. The annual stability can be less than ±3μV. After high temperature calibration, they can be used as a secondary standard for high temperature value reporting. The positive copper of T-type thermocouples has poor oxidation resistance at low temperatures, so the lower limit of the application temperature is limited.

Because the thermoelectric characteristics of various types of thermocouples are different, they are used within the scope of their linear segments. At the same time, each type of thermocouple has a minimum temperature limit for application.