When using an S-type thermocouple for temperature measurement, what must it be used with?

S-type thermocouple is a commonly used measurement method in temperature measurement. Its measurement principle is based on the Seebeck effect, that is, in a loop composed of two conductors or semiconductors of different components, when there is a temperature difference between the two ends, a thermoelectric potential will be generated in the loop. The magnitude of this thermoelectric potential is proportional to the temperature difference between the two ends. By measuring this thermoelectric potential, the temperature difference between the two ends can be known, and thus the temperature of the object being measured can be known.

However, since the output signal of the S-type thermocouple is often weak and will be interfered by many factors, such as the change of thermoelectric potential with the change of measured temperature, electromagnetic interference, etc. In order to improve the accuracy and stability of the measurement, we need to take some measures to reduce these interferences. One of the effective methods is to use compensation wires.

The compensation wire is a special wire with two different metal materials embedded inside, which is generally used in conjunction with thermocouples. The function of the compensation wire is to extend the temperature signal of the thermocouple to a place far away from the measurement, such as the control room or the location of the display instrument. The advantage of this is that the measurement signal can be brought back to the control room from the site, avoiding the loss and interference of the signal during long-distance transmission. At the same time, in the control room, we can use some advanced signal processing technologies and algorithms to further reduce interference and errors and improve the accuracy and stability of the measurement.

When using thermocouples for temperature measurement, we need to select appropriate compensation wires according to different measurement scenarios and needs. Generally speaking, the compensation wire needs to be consistent with the corresponding thermocouple model to ensure that the transmitted signal is accurate. In addition, the selection of compensation wires also needs to consider factors such as its material, resistance, and temperature resistance level to ensure that it can meet the measurement requirements.

In short, when using thermocouples for temperature measurement, it must be used in conjunction with compensation wires, which can improve the accuracy and stability of the measurement. At the same time, we also need to select appropriate compensation wires and other equipment according to specific measurement needs and scenarios to ensure the accuracy and reliability of the measurement results.