Compliance and audits
Calibration requirements by ISO standard
There is no single ISO standard that covers calibration for everyone. What applies to you depends on what your quality system is certified against and whether you run a calibration lab or just use measuring equipment in production. This guide summarizes what each major standard asks for, and the requirements they share.
Is there a single ISO standard for calibration?
No. Two standards are about calibration itself: ISO/IEC 17025 sets the competence requirements for testing and calibration laboratories, and ISO 10012 defines a measurement management system for the equipment and processes behind measurement. Most quality standards, including ISO 9001, ISO 13485, AS9100, and IATF 16949, have no separate calibration standard. They fold the calibration requirements into one clause on monitoring and measuring resources.
So the requirements that apply to you follow your certification. A production shop certified to ISO 9001 works from clause 7.1.5. A medical device manufacturer works from ISO 13485 clause 7.6. A calibration laboratory works from ISO/IEC 17025. This is a starting point for understanding scope, not a substitute for the standard text or your assessor's interpretation.
The requirements every standard shares
Across ISO 9001, ISO/IEC 17025, ISO 13485, AS9100, and IATF 16949, the calibration expectations rhyme. If you can satisfy the five points below, you are close to what most auditors look for, whatever the clause number.
- Calibrate or verify against traceable standards. Equipment that affects the validity of results is calibrated or verified against a reference with a documented link to a national or international standard (the SI), or to a stated basis where no standard exists.
- Do it at defined intervals. Each instrument has a calibration interval set on a documented basis, not left to chance.
- Identify calibration status. Anyone can tell whether an instrument is in calibration, due, or out of service, so nobody unknowingly uses equipment that is out of date.
- Safeguard against invalidating adjustments. Settings and adjustments that would invalidate the calibration are protected.
- Act when something is found out of tolerance. When an instrument is found out of calibration, you assess and record the validity of previous results and act on any affected product or measurements. Records are retained throughout.
ISO 9001: clause 7.1.5
ISO 9001:2015 places calibration in clause 7.1.5, Monitoring and measuring resources. Clause 7.1.5.1 requires that the resources you use to verify conformity are suitable, maintained to stay suitable, and supported by retained records. Clause 7.1.5.2, Measurement traceability, applies when traceability is a requirement or you consider it essential: instruments are calibrated or verified against standards traceable to international or national standards (or the basis is recorded), identified to determine their status, and safeguarded against adjustments that would invalidate them.
When an instrument is found unfit, ISO 9001 expects you to determine whether previous measurement results were affected and take appropriate action.
Can you calibrate in-house under ISO 9001?
Yes. ISO 9001 does not require an outside laboratory, and it does not require the lab you use to be accredited. Clause 7.1.5.2 requires that instruments are calibrated against standards traceable to international or national standards. You can meet that in-house if the reference standards you calibrate against were themselves calibrated by a traceable source, so the chain back to the SI stays unbroken.
In practice, an auditor reviewing in-house calibration looks for four things: a documented procedure for each type of calibration you perform, evidence that the people doing the work are competent, current certificates for your reference standards showing their traceability, and a record of each in-house calibration with the readings, the standard used, and the result.
External accredited calibration still earns its keep for your reference standards themselves, for instruments that need tight uncertainty, and for customers who ask for ISO/IEC 17025 certificates. Most programs land on a mix: reference standards go out to an accredited lab, and working instruments are calibrated in-house against them. Axiospec tracks both in one place. In-house events record the reference standard used, and instruments on external calibration carry the vendor, the scheduled date, and an out-for-calibration status, so nothing disappears into a courier box.
ISO/IEC 17025: clauses 6.4 and 6.5
ISO/IEC 17025:2017 is the standard for the competence of testing and calibration laboratories, so its calibration requirements are the most detailed. Clause 6.4, Equipment, requires that equipment affecting results is calibrated, uniquely identified, labeled with its calibration status, and supported by records of every calibration, intermediate check, and adjustment. Clause 6.5, Metrological traceability, requires that measurements are traceable to the SI through an unbroken chain of calibrations, each contributing to the measurement uncertainty.
Because a 17025 lab issues results that others rely on, its record and uncertainty requirements go beyond what a production ISO 9001 site needs.
ISO 13485: clause 7.6
ISO 13485:2016 covers quality management for medical devices, and clause 7.6, Control of monitoring and measuring equipment, carries the calibration requirements. Equipment is calibrated or verified at defined intervals against standards traceable to international or national standards (with the basis recorded where none exists), adjusted as necessary, identified to determine its status, and safeguarded from adjustments that would invalidate results. When equipment is found not to conform, you assess and record the validity of previous results and take action on the equipment and any affected product. Records are maintained throughout.
AS9100: aerospace, on top of ISO 9001
AS9100D uses ISO 9001:2015 as its base, so calibration still lives in clause 7.1.5, but aerospace adds expectations that matter at audit. Suppliers are expected to control measuring equipment tightly, maintain a register with recall so out-of-calibration equipment can be found and evaluated, account for the environmental conditions of measurement, and keep the records primes and Nadcap assessors ask for.
IATF 16949: automotive, with MSA
IATF 16949:2016 sits on ISO 9001 and adds automotive requirements. Alongside calibration and verification records (clause 7.1.5.2.1) and requirements for external calibration laboratories (clause 7.1.5.3), it calls for measurement systems analysis, clause 7.1.5.1.1, to study the variation in your measurement systems, typically through Gage R&R studies.
ISO 10012: a measurement management system
ISO 10012:2003 is not a certification most companies pursue on its own, but it is the reference for a measurement management system. It defines metrological confirmation (the calibration plus the verification that an instrument is fit for its intended use) and the control of measurement processes. It is a useful framework when you want your calibration program to be systematic rather than ad hoc.
How often does equipment need to be calibrated?
No standard sets a universal interval. They require calibration at defined intervals and expect the interval to have a documented, defensible basis rather than a number pulled from the air. Common inputs are the manufacturer's recommendation, how the instrument is used and how critical its measurements are, its history of staying in tolerance, and any regulatory or customer requirement.
A risk-based, reliability-informed interval is easier to defend than a flat one-year default. Axiospec computes a reliability-based recommended interval from each instrument's own calibration history so the number has evidence behind it, but the interval you set stays your decision.
How Axiospec helps you meet these requirements
Axiospec is one system for the requirements these standards share. It keeps a live calibration status on every instrument, records the reference standard and certificate behind each calibration so traceability is visible, and writes every event to a tamper-evident ledger with timestamps and e-signatures. When an instrument is found out of tolerance, you reverse-trace the measurements and product it touched. The calibration form and certificate adapt to the standards you select, and you can export a complete, audit-ready pack for any instrument in one click.
Whether you pass an audit still depends on your processes, scope, and assessor. Axiospec helps you produce clean, traceable, defensible records so that part is not the problem.
Put it into practice
Import your asset registry in an afternoon, log every calibration to a tamper-evident audit trail, and produce records on demand. Prefer to see it first? Take a self-guided tour with sample data, no signup required.
Axiospec is a documentation and workflow tool. It helps you keep clean, traceable, audit-ready records; certification depends on your own processes, scope, and assessor.
More like this, by email
A short series of practical calibration guides like this one. No spam, unsubscribe with one click.