Calibration
What a definition is not
A definition is SPEQ’s plain-language decode of how a term is used in practice, cited to the documents that define it. It is a practitioner reference, not legal or regulatory advice, it does not replace the definition in the source, and where a regulator’s wording differs the regulator’s wording governs.
The documented comparison of a measuring instrument’s output against a traceable reference standard, and any adjustment needed to bring its readings within specified tolerance, performed at a defined interval so that instruments used to make GxP-critical measurements remain accurate, precise, and traceable to a recognized national or international standard.
Calibration answers a narrower question than qualification: not “does this equipment work as designed,” but “does this specific measurement — this thermometer, this balance, this pressure gauge — read true.” The reference standard used must itself be traceable through an unbroken chain back to a national metrology institute, and the comparison, tolerance, and any adjustment made are all recorded on a calibration certificate or label tied to the instrument.
An out-of-tolerance calibration result is not routine paperwork — it triggers an impact assessment of every measurement the instrument produced since its last known-good calibration, which can cascade into batch-record review and deviation investigations if product-critical data is implicated.
- —Verifies a specific measurement against a traceable reference standard, not overall equipment function
- —Traceability runs back to a national or international metrology standard
- —Performed at a risk-based, defined interval and documented on a certificate or instrument label
- —An out-of-tolerance result requires impact assessment of measurements taken since the last valid calibration
- —Distinct from qualification — calibration is a subset of the broader IQ/OQ verification
21 CFR 211.68; EU GMP Annex 15; ISO/IEC 17025:2017
Frequently asked questions
What is Calibration?
The documented comparison of a measuring instrument’s output against a traceable reference standard, and any adjustment needed to bring its readings within specified tolerance, performed at a defined interval so that instruments used to make GxP-critical measurements remain accurate, precise, and traceable to a recognized national or international standard.
Which regulations cover Calibration?
21 CFR 211.68; EU GMP Annex 15; ISO/IEC 17025:2017