Calibration is defined as the comparison of a measurement standard, instrument, or item with a standard or instrument of higher accuracy to detect and quantify inaccuracies and to report or eliminate those inaccuracies by adjustment.
Since the term calibration is associated with an adjustment in either the instrument or software, these adjustments should be minimized as much as possible.
Sometimes performing frequent adjustments to provide the “most accurate data possible” can be self-defeating and be the cause of additional measurement uncertainty.
Therefore, quality control procedures that include verification checks and multi-point calibration verifications are considered “checks without correction” and are used to ensure the instruments are within the calibration tolerances.
Usually these tolerances have been developed so that as long as the instrument is within these tolerances, adjustments do not need to be made. However, verifications should be implemented at reasonable frequencies to avoid invalidating significant amounts of data.