Clause 7.1.5 of ISO 9001 requires that, when measurement is used to verify the conformity of a product, the equipment be calibrated or verified at specified intervals against standards traceable to national or international measurement standards (normally through laboratories accredited by the national accreditation body), identified as to its status and protected against adjustment and damage. Equipment in use with the calibration expired is one of the most frequent nonconformities in audits — and one of the easiest to prevent with a living control.
The minimum control per instrument: a unique identification (physical label with code and due date); use and location (which critical measurement it serves); the interval, defined by use and criticality (a caliper for final inspection: 6 to 12 months; a thermometer on a critical process: possibly shorter); and the acceptance criterion — the point that separates a mature control from a collection of certificates: define the maximum permissible error as a function of the tolerance the instrument verifies (rule of thumb: uncertainty + error <= 1/10 to 1/4 of the tolerance) and EVALUATE every certificate against that criterion when you receive it. A certificate filed without evaluation is money thrown away.
And here is the item almost everyone forgets: the action when the instrument fails. Clause 7.1.5.2 requires evaluating the validity of previous measurements taken with equipment found outside the criterion — in other words: what was released with that caliper since the last good calibration? Record that analysis (sampling for re-inspection, batch risk assessment) in the control itself.
The template below brings the inventory with all of those fields, including one failed instrument that was properly handled — exactly the record the auditor asks to see.