When calibrating thermocouples with a dry block calibrator, the temperature uniformity is affected by various factors. The distribution of the heating elements of the dry block calibrator is an important factor. If the heating elements are not evenly distributed, it will lead to an uneven temperature field inside the dry block calibrator. The thermal insulation performance of the dry block calibrator will also affect the temperature uniformity. Poor thermal insulation may cause uneven heat loss. In addition, if the stirring device (if any) of the dry block calibrator does not work properly and cannot heat the internal medium evenly, it will also cause uneven temperature. The position of the thermocouple in the dry block calibrator also has an impact. Being in different positions may sense different temperatures. Therefore, when using a dry block calibrator to calibrate a thermocouple, these factors should be fully considered and corresponding measures should be taken to ensure temperature uniformity.