When using a dry block calibrator to calibrate a thermocouple, it is first necessary to ensure that the temperature range of the dry block calibrator can cover the measurement range of the calibrated thermocouple. If the upper or lower temperature limit of the dry block calibrator cannot meet the range requirements of the thermocouple, the calibration result will be inaccurate. Before calibration, the dry block calibrator needs to be preheated to reach a stable temperature state. Generally, the preheating time should be carried out according to the requirements of the dry block calibrator's manual, usually not less than 30 minutes. The insertion depth of the thermocouple is also a key factor. Inserting it too shallow will lead to inaccurate measurements, and it should be inserted to the appropriate depth according to the standard requirements. During the calibration process, pay attention to the temperature uniformity of the dry block calibrator to avoid errors caused by non-uniform temperature. At the same time, the dry block calibrator should be calibrated and verified regularly to ensure its own accuracy.