1. The selection of compensation wires must be based on the type of thermocouple used and the intended application. For example, the compensation wire of the K-type thermocouple should be selected, and the operating temperature range should be chosen according to the usage scenario. The typical working temperature for kx is -20 to 100 ℃, with a wide range of -25 to 200 ℃. The ordinary level error is ± 2.5 ℃, and the precision level is ± 1.5 ℃.

2. Connect the two contacts as close as possible to the thermocouple terminal, and try to maintain consistent temperature between the two contacts. The temperature at the connection point with the instrument terminal should be as consistent as possible. Where there is a fan in the instrument cabinet, the contact point should be protected from the fan blowing directly to the contact point.

3. Due to the low signal of the thermocouple, which is at the microvolt level, if the distance is too long, signal attenuation and strong electrical interference coupling in the environment can cause distortion of the thermocouple signal, resulting in inaccurate temperature measurement and control. In severe cases, temperature fluctuations may occur during control. Based on our experience, it is usually better to control the length of the thermocouple compensation wire within 15 meters. If it exceeds 15 meters, it is recommended to use a temperature transmitter to transmit the signal. The temperature transmitter converts the potential value corresponding to the temperature into direct current for transmission, and has strong anti-interference ability.

To improve the anti-interference performance of thermocouple connection wires, shielded compensation wires can be used. For situations where there are many sources of interference on site, the effect is better. But it is necessary to strictly ground the shielding layer, otherwise the shielding layer will not only fail to provide shielding, but also enhance interference.