Do You Know Your ISO From Your Elbow?

We are often asked for a ‘UKAS certificate’ as opposed to a ‘Traceable certificate’ but as UKAS do not actually issue a certificate for calibration the correct term is an ISO/IEC:17025 accredited certificate. So what is the difference between the two, and more importantly, which applies more to your needs?

An ISO/IEC:17025 accredited certificate means the procedures and criteria have been specifically developed to determine technical competence for that particular calibration type. Through independent assessment that evaluates all the factors that affect accuracy and repeatability of the calibration. This service is traceable back to National and International standards whereas a traceable or in-house certificate (although generally traceable to national standards) is not necessarily traceable back to an international standard.

ISO/IEC:17027 certificates are a legally recognized document whereas a traceable certificate is not.

Lab calibration procedures, personnel and uncertainties have all been assessed by UKAS (ISO:17025 accrediting body) for an ISO:17025 certificate whereas for a traceable certificate this will not be the case.

In our experience, the service or certificate type you require will depend on your own quality system. If you are an ISO:9001 accredited company then in most cases a traceable or in-house certificate of calibration will suffice. However, you may be an ISO:9001 where your quality manual specifies that calibration must be done to an international standard in which case you will need an ISO/IEC:17025 certificate.

CET Calibration have the experience to offer advice as to which would be best for you. Please contact our technical team on 01246 820960 or email