b type compensation wire must be correctly selected according to the type of thermocouple used and the occasion used. For example, type k couples should choose the compensation wire of type k couples, according to the use of the occasion, choose the operating temperature range. Usually kx operating temperature of -20 ~ 100℃, wide range of -25 ~ 200℃. The common grade error is ±2.5℃, and the precision grade error is ±1.5℃.

And thermocouple terminal 2 contacts as close as possible, as far as possible to keep the temperature of 2 contacts *. The connection between the terminal and the instrument should be as warm as possible. Where there is a fan in the instrument cabinet, the contact should be protected from the fan blowing directly to the contact. In order to improve the interference resistance of thermocouple wire, shielding compensation wire can be used. For the site interference sources more occasions, the effect is better. But the shielding layer must be strictly grounded, otherwise the shielding layer not only does not play a shielding role, but enhances the interference.

Because the signal of the thermocouple is very low, for the microvolt level, if the use of the distance is too long, the attenuation of the signal and the interference of strong electricity in the environment, enough to make the signal distortion of the thermocouple, resulting in the measurement and control of the temperature is not accurate, serious in the control of temperature fluctuations.

According to our experience, it is usually better to use the length of the thermocouple compensation wire to control within 15 meters, if more than 15 meters, it is recommended to use the temperature transmitter for signal transmission. Temperature transmitter is the temperature corresponding to the potential value into direct current transmission, strong anti-interference.