B type compensation wire must be selected correctly according to the type of thermocouple used and the situation used. For example, the type K couple should choose the compensation wire of the Type K couple, depending on the service situation, choose the operating temperature range. Usually kX operating temperature is -20 ~ 100℃, a wide range of -25 ~ 200℃. The error of ordinary grade is ±2.5℃, and that of precision grade is ±1.5℃.

As close as possible to the two contacts of the thermocouple terminals, try to keep the temperature of the two contacts *. The temperature of the connection with the instrument terminal is as high as possible. Where there is a fan in the instrument cabinet, the contact should be protected from blowing the fan directly to the contact. In order to improve the anti-interference of thermocouple connection wire, shielded compensation wire can be used. The effect is better when there are many interference sources. However, the shielding layer must be strictly grounded, otherwise the shielding layer not only did not play the role of shielding, but enhance the interference.

Because the signal of thermocouple is very low, for microvolt level, if the distance used is too long, the signal attenuation and the interference coupling of strong electricity in the environment, enough to make the signal distortion of thermocouple, resulting in inaccurate measurement and control of temperature, in the control of serious will produce temperature fluctuations.

Based on our experience, it is usually better to use thermocouple compensation wires within 15 meters in length. If they exceed 15 meters, it is recommended to use temperature transmitters to transmit signals. Temperature transmitter is the temperature of the corresponding potential value into dc current transmission, strong anti-interference.