What Is Calibration?

Calibration is the comparison of measured values taken from a device under test, with those of a standard of known accuracy, for the purpose of detecting and reporting, or eliminating by adjustment, errors in the instrument tested. The calibration standard is normally traceable to a national standard held by a National Metrological Institute. The comparison results in either:

• No significant error found on the device under test.
• A significant error being found but no adjustment made.
• A significant error being found, and an adjustment made to correct the error to an acceptable level.

The term calibration means the act of comparison. A compliant calibration does not necessarily include adjustments to bring the instrument up to specified performance. It may only require evidence of performance to within manufacturer’s specification.