When using thermocouple compensation wires, it is necessary to pay attention to the correct model

When using thermocouple compensation wires, please pay attention to the number of clicks that match the model: 199 Release time: 2009-10-14 13:26:39

Two different materials of conductors or welded semiconductors a and b form a closed circuit. When there is a temperature difference between the two attachment points 1 and 2 of conductors a and b, an electromotive force is generated between them, and a large current is generated in the circuit, which is called the thermoelectric effect. Thermocouples utilize this effect to function.

Commonly used thermocouples can be divided into two categories: standard thermocouples and non-standard thermocouples. The standard thermocouple used refers to a thermocouple that is specified in the national standard for the relationship between thermoelectric potential and temperature, allowable errors, and a unified standard scale, and has a matching display. Non standardized thermocouples are not as suitable for use as thermocouples with standardized ranges or orders of magnitude, and generally do not have a unified scale. They are mainly used for measurements in special situations.

The material of thermocouples is generally valuable (especially when using precious metals), and the distance from the temperature measuring point to the instrument is far. In order to save the material of thermocouples and reduce costs, compensation wires are usually used to extend the cold end (free end) of thermocouples to a temperature stable control room and connect it to the instrument terminals. It must be pointed out that the function of the thermocouple compensation wire is only to move the cold terminal of the thermocouple to the instrument terminal in the control room, and cannot eliminate the influence of temperature changes in the cold terminal on temperature measurement, and cannot be compensated. Therefore, in order to compensate for the cooling temperature t0&ne, other correction methods are needed to affect the temperature measurement at 0 ℃.

When using thermocouple compensation wires, it is important to ensure consistency in form and avoid polarity errors. The temperature at the connection end between the compensation wire and the thermocouple should not exceed 100 ℃.

Thermal resistance is a commonly used temperature detector in the medium and low temperature range. Its main characteristics are high measurement accuracy and stable performance. Among them, platinum has the highest resistance measurement and has been widely used not only in industrial temperature measurement, but also in standard instruments.