ISO 13485:2016 calibration requirements - what do medical device manufacturers need to know?

ISO 13485:2016 calibration requirements are set out in clause 7.6, which requires medical device manufacturers to control the monitoring and measuring equipment used to prove products meet specified requirements. In practice, this means calibrating or verifying that equipment at specified intervals or before use against traceable standards, recording the results, protecting equipment from damage and unauthorised adjustment, validating measurement software and assessing earlier results whenever an instrument is found out of tolerance. UK approved bodies, EU notified bodies and, since February 2026, the US FDA all audit against these controls.

What does ISO 13485 clause 7.6 require?

Clause 7.6 of ISO 13485:2016 requires a documented procedure for monitoring and measurement, plus five controls over the equipment itself. Where necessary to ensure valid results, measuring equipment must:

be calibrated, verified or both at specified intervals or before use, against standards traceable to international or national measurement standards (or, where none exist, a recorded basis for calibration);
be adjusted or re-adjusted as necessary, with those adjustments recorded;
carry identification so its calibration status can be determined;
be safeguarded from adjustments that would invalidate the measurement result;
be protected from damage and deterioration during handling, maintenance and storage.

Compared with ISO 9001, the medical device standard is more prescriptive, explicitly requiring documented procedures, retained records and software validation. With more than 31,000 ISO 13485 certificates issued worldwide according to the ISO Survey, it is the common benchmark for medical device quality management systems (QMS).

What is the difference between calibration, verification and validation?

Calibration compares an instrument against a traceable reference, verification confirms it meets specified requirements, and validation confirms that a process or piece of software consistently does what it is intended to do. Auditors will expect you to apply the right one.

Activity	What it confirms	ISO 13485 reference	Example
Calibration	An instrument's readings against a traceable reference standard, with stated uncertainty	7.6	A torque wrench checked against a reference transducer
Verification	Equipment meets specified requirements, often a quick check before use	7.6	A balance checked with a certified test weight
Validation	Software or a process consistently produces the intended result	7.6, 7.5.6	Data-logging software used to record test results

Software used to monitor and measure requirements must be validated before initial use and after changes, proportionate to the risk associated with its use.

What happens when equipment is found out of tolerance?

When measuring equipment does not conform to requirements, clause 7.6 requires the manufacturer to assess and record the validity of previous measurement results, then take appropriate action on both the equipment and any affected product.

This is where measurement uncertainty and good records matter. An "as found" result on the calibration certificate tells you how far the instrument had drifted, so you can decide which batches, if any, need re-inspection.

How do you demonstrate calibration compliance during an audit?

You demonstrate compliance by showing auditors a controlled, traceable system: an equipment register, defined intervals, current certificates, status labels, out-of-tolerance investigations and evidence that your calibration provider is competent for the work performed.

The audience for that evidence depends on your markets. In Great Britain, the MHRA regulates devices under the Medical Devices Regulations 2002 and designates UK approved bodies to carry out conformity assessments. For the EU, EN ISO 13485:2016 is a harmonised standard under the Medical Device Regulation, so notified bodies audit against it. For exporters to the US, the FDA's Quality Management System Regulation has incorporated ISO 13485:2016 by reference since 2 February 2026. The FDA has also confirmed that an ISO 13485 certificate will not exempt a manufacturer from inspection, so records must stand up on their own.

Why is UKAS accreditation the gold standard for ISO 13485 traceability?

ISO 13485 does not mandate an accredited calibration provider, but UKAS accreditation to ISO/IEC 17025 is the most widely recognised independent evidence that calibrations are competent and traceable.

According to UKAS, accredited calibration provides confidence that equipment is calibrated "through an unbroken chain to national/international standards", and certificates from accredited laboratories are accepted as technically equivalent across signatory countries. UKAS also warns that ISO 9001 certification is no substitute, as it does not verify technical competence. Always check that the specific calibration you need sits within the laboratory's schedule of accreditation.

Support your ISO 13485 calibration requirements with DM

Meeting ISO 13485 calibration requirements depends on reliable measurements, traceable results and records you can confidently present during an audit. Working with an experienced calibration partner helps you maintain these controls while keeping essential equipment available for production.

At DM, we provide electrical, mechanical, dimensional, pressure and temperature calibration, with laboratory and on-site services to suit your operational requirements. As UKAS Calibration Laboratory No. 0143, we offer accredited calibration within our published scope to support your quality management system. To find out more, download our guide below.