For force measurement, the process of calibration is the comparison of applied forces indicated by a measurement system under test to a calibration standard. The traceability of the standard used defines the resulting range and accuracy of the system being tested
Hardness Calibration should be performed on a periodic basis to verify that the accuracy of the instrument is within the manufacturer’s stated tolerances for the grade or model. As a hardness tester repeatedly measures the relative resistance of materials to denting, bending, or scratching, it can become misaligned. Calibration and adjustment will be required to restore its reliability.