Here are some commonly used thermocouple calibration tools:

1. Constant temperature bath: 

As a temperature source, it is used to provide a stable and accurate temperature environment to calibrate and verify the performance of thermocouples at different temperatures. The temperature stability of a constant temperature bath is usually relatively high (such as within ±0.1℃) and can cover the required calibration temperature range.

2. Standard thermocouple: 

As a reference standard, its precision grade is higher than that of the calibrated thermocouple. The thermoelectric potential and temperature relationship of the standard thermocouple has been accurately determined and is used for comparison with the calibrated thermocouple to determine the error of the calibrated thermocouple.

3. Digital multimeter: 

Used for measuring the electromotive force generated by thermocouples. It has high measurement accuracy and stability and can accurately read the tiny voltage signal output by the thermocouple and convert it into the corresponding temperature value.

4. Ice point device: 

A common zero-point calibration tool. Zero-point calibration is to check whether the thermocouple outputs zero electromotive force at zero temperature. Place the measuring end of the thermocouple in the ice point device and record the output electromotive force after the temperature is stable. If the electromotive force is zero or close to zero, it means that the zero-point calibration of the thermocouple is qualified.

5. Thermocouple verification furnace: 

It is one of the main components of a thermocouple detection device. Together with a temperature control device, an electrometer, and a standard thermocouple, it forms a complete set of detection devices for measuring various industrial thermocouples. Its main function is to place the thermocouple in the verification furnace and complete the calibration by the comparison method through controlling the temperature and reading the measuring instrument. As a standard instrument for calibration, the thermocouple verification furnace needs to maintain high accuracy, so it needs to be tested regularly.

6. Temperature equalizing block: 

In thermocouple calibration, the second-class standard platinum-rhodium 10-platinum thermocouple and the calibrated thermocouple are usually bundled together and placed in the qualified temperature field of a tube furnace to complete the calibration by the comparison method. The uniformity of the temperature field of the tube furnace is an important factor to ensure the accuracy of the calibration results. The temperature equalizing block can improve the uniformity of the temperature field and improve the calibration accuracy.