During resistance calibration, the instrument is compared against a known reference source, typically a precision resistor, to ensure that it is measuring accurately. The calibration process involves a series of tests at different resistance 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 resistance measuring instruments is important to ensure accurate measurements, as the accuracy of the instrument can drift over time due to various factors such as exposure to extreme temperatures and physical damage. The frequency of calibration depends on several factors, including the industry, application, and the frequency of use. Typically, resistance measuring instruments should be calibrated at least once a year, but some applications may require more frequent calibration.