Thermocouple wires must be correctly selected according to the type of the thermocouple as well as the operating environment. For example, we should choose the corresponding K-type thermocouple wire for K-type thermocouple and choose appropriate operating temperature range based on the operating environment. Normally, the operating temperature of K is between -20 and 100℃, the wide range is -25 ~ 200℃.

The connection method

Making the two thermocouple connection points as close as possible, and keeping the temperature of the two connection points as close as possible. The temperature should be consistent with the connection point of the instrument terminal. At the spots where the fan is located in the instrument cabinet, the connection point should not be blew by the fan.

Length for use

Since the thermocouple signal is at very low microvolt level, if it’s long distance, the signal attenuation and the interference of strong electricity in the environment could be mixed together. This is enough to cause the thermocouple signal distortion, resulting in inaccuracy of measurement and control of the temperature, or even temperature fluctuations when it’s serious.

According to our experience, it is usually better to limit the length of the thermocouple compensating wire within 15 meters. When it’s over 15 meters, we recommend to use temperature transmitter for signal transmission. The temperature transmitter converts the electric potential value corresponding to the temperature into DC current DC4-20mA for transmission, with strong anti-interference ability.

Method of wiring

Thermocouple compensating wires must be wired away from power lines and any interference sources. When crossing is unavoidable, adopt the cross-laying method instead of the parallel laying method.

Shielded compensating wires

In order to improve the anti-interference performance of thermocouple connection wires, we can use the shielded compensating wire which is more effective in the environment with strong interference. Make sure the shielding layer is strictly grounded, or the shielding layer will not shield the signal interference but actually enhance it.