Note on particle counters: This page is for general information only. Techmaster does not calibrate particle counters of any make or model, and particle counters are not on our ANAB ISO/IEC 17025 scope (certificate AC-1736). Techmaster only performs calibration services that are covered by our scope. For particle counter calibration, please contact your instrument’s manufacturer or its authorized service provider, and follow any service requirements they specify. If you prefer, send us your request and, with your permission, we will forward it to the manufacturer. See what is on our accredited scope.
ISO 17025: the standard for testing and calibration labs
What is ISO 17025?
ISO/IEC 17025 is published jointly by the International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC). Its full title is “General requirements for the competence of testing and calibration laboratories”. The current edition, ISO/IEC 17025:2017, was published in November 2017, and accredited laboratories had until November 2020 to transition to it.
The standard applies to any organization that performs testing, calibration or sampling, whether it is an independent calibration lab, a manufacturer’s in-house lab or a government lab. It is the basis on which accreditation bodies assess laboratories, so “ISO 17025 accredited” is the recognized way for a lab to show that its results can be trusted.
What does ISO/IEC 17025 require?
The requirements sit in clauses 4 to 8. Clauses 4 to 7 cover how the lab is organized and how it does the technical work; clause 8 covers the management system.
| Clause | Covers | What it means in practice |
|---|---|---|
| 4 · General requirements | Impartiality and confidentiality | The lab identifies and manages risks to impartial results and protects customer information. |
| 5 · Structural requirements | Legal entity, management and defined activities | The lab is a legally responsible entity with defined responsibilities and a documented range of laboratory activities. |
| 6 · Resource requirements | Personnel, facilities, equipment, metrological traceability, externally provided services | Competent staff, controlled environmental conditions, calibrated equipment traceable to SI units (in the US typically through NIST), and control of subcontracted work. |
| 7 · Process requirements | From contract review to reporting | Review of requests, method selection and validation, handling of items, technical records, measurement uncertainty, ensuring validity of results, reporting, complaints, nonconforming work and control of data. |
| 8 · Management system requirements | Option A or Option B | Document control, records, risks and opportunities, improvement, corrective action, internal audits and management review. Option B lets a lab rely on an ISO 9001 system that meets these requirements. |
Two requirements matter most to anyone buying calibration. Metrological traceability means every result links through an unbroken chain of calibrations to SI units. Measurement uncertainty means the lab states how confident it is in each result. Our guides to building a measurement uncertainty budget and lab environmental conditions go deeper, and intermediate checks explains how labs keep results valid between calibrations.
Is a lab ISO 17025 certified or accredited?
A laboratory is accredited to ISO/IEC 17025, not certified. Accreditation is issued by an accreditation body after it assesses the lab’s technical competence, not only its paperwork. “ISO 17025 certified” is a common phrase, but certification is the term used for management-system standards such as ISO 9001, where a certification body confirms a system is in place without assessing measurement competence.
The distinction matters in an audit: an auditor will ask for the lab’s accreditation certificate and its scope, and check that the calibration you bought is on that scope. What is an accredited calibration laboratory? covers this in more detail.
How does a laboratory get ISO 17025 accreditation?
- Build the system. The lab documents its methods, trains and authorizes staff, establishes traceability for its standards and calculates measurement uncertainty for each calibration it will offer.
- Check itself. Internal audits and a management review confirm the system meets every clause before the lab applies.
- Apply to an accreditation body such as ANAB or A2LA, stating the parameters and ranges it wants on its scope.
- Assessment. Assessors review the documentation, then visit the lab to witness calibrations, interview staff and check records. Proficiency testing or interlaboratory comparisons show the lab’s results agree with others.
- Close findings. The lab corrects any nonconformities and shows evidence of the fix.
- Accreditation and surveillance. The body grants accreditation with a published scope, then keeps assessing the lab periodically for as long as it stays accredited.
Accreditation bodies that sign the ILAC Mutual Recognition Arrangement accept each other’s accreditations, so a certificate from an ILAC-recognized accredited lab is accepted by customers and regulators in other signatory countries.
What is an accreditation scope and a CMC?
An accreditation never covers “everything”. The scope lists each parameter the lab is accredited for, the range, and the smallest uncertainty the lab can achieve for it, called the calibration and measurement capability (CMC). A lab accredited for DC voltage to 1,000 V is not accredited for RF power, and a lab accredited to 10,000 psi is not accredited at 15,000 psi.
Always check the scope for your instrument’s parameters and ranges. Work outside the scope can still be calibrated, but the certificate will be NIST-traceable rather than ISO/IEC 17025 accredited. Accredited vs NIST-traceable calibration explains the difference, and subcontracted calibration covers what happens when a lab sends work elsewhere.
How is ISO 17025 different from ISO 9001?
| ISO/IEC 17025 | ISO 9001 | |
|---|---|---|
| Applies to | Testing and calibration laboratories | Any organization |
| Recognition | Accreditation by an accreditation body | Certification by a certification body |
| Assesses technical competence | Yes: methods, staff, equipment, traceability, uncertainty | No: the management system only |
| Result on paper | Accredited certificate with measurement uncertainty, for parameters on the scope | Certificate of registration for the quality system |
| Relationship | A 17025 lab can run its management system under Option B, using an ISO 9001 system that meets clause 8. ISO 9001 calibration requirements explains what 9001 asks of your own equipment. | |
Industry standards build on both: AS9100 in aerospace, ISO 13485 for medical devices and IATF 16949 in automotive all expect calibration from competent, often accredited, laboratories.
What should an ISO 17025 calibration certificate contain?
- Identification of the instrument, the customer, the lab and the method used
- As-found and as-left results at each calibration point
- The measurement uncertainty for each result
- A statement of metrological traceability
- Any statement of conformity with the decision rule applied, as described in decision rules and guardbanding
- The accreditation body’s mark, for results within the lab’s scope
How to read an ISO 17025 calibration certificate walks through each field.
What changed in ISO/IEC 17025:2017?
The 2017 edition replaced the 2005 version. It restructured the standard around processes, added risk-based thinking in place of the old preventive-action clause, introduced Options A and B for the management system, made decision rules for statements of conformity explicit, and brought in requirements for electronic records and laboratory information systems. The transition period for accredited labs ended in November 2020.
How is Techmaster accredited?
Techmaster Electronics is accredited to ISO/IEC 17025:2017 by ANAB under certificate AC-1736. Four of our laboratories are on the scope: Vista and Santa Clara, California, Orlando, Florida, and San Antonio, Texas. The scope covers electrical, RF and microwave to 50 GHz, torque, pressure, dimensional, vibration, environmental chambers and more, with each capability attributed to the lab that holds it.
Some instruments are not on our scope. We do not calibrate particle counters; patient simulators and optical radiometers we calibrate with NIST-traceable certificates. Our published scope lists every accredited parameter, range and uncertainty, and our accredited calibration services page shows what we calibrate.
ISO 17025 FAQ
What does ISO 17025 mean?
Is a lab ISO 17025 certified or accredited?
Is ISO 17025 accreditation mandatory?
Who accredits laboratories to ISO 17025 in the United States?
What is the difference between ISO 17025 and ISO 9001?
Does ISO 17025 accreditation cover everything a lab calibrates?
Need ISO/IEC 17025 accredited calibration?
Send your instrument list. We confirm which items are on our ANAB scope before you ship anything.
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Khanh Nguyen is the Marketing Manager at Techmaster Electronics, a B2B marketing leader covering the test, measurement, and ISO/IEC 17025 accredited calibration industry in the United States.