During thermocouple calibration, the thermocouple is compared against a known reference source, typically a high-accuracy temperature standard such as a calibrated thermometer, to ensure that it is measuring accurately. The calibration process involves a series of tests at different temperature levels, and the results are compared with the reference values. Calibration certificates are then provided to document the calibration process and results, providing traceability and peace of mind for the customers.

Regular calibration of thermocouples is important to ensure accurate temperature measurements, as the accuracy of the thermocouple can drift over time due to factors such as physical damage, exposure to extreme temperatures or humidity, or aging of the thermocouple wires. The frequency of calibration depends on several factors, including the industry, application, and the frequency of use. Typically, thermocouples should be calibrated at least once a year, but some applications may require more frequent calibration.