ISO 17025 Calibration

[jweaveman1]

We are a medical device company certified to ISO 13485 and are trying to understand the difference between a standard NIST calibration and a ISO 17025 calibration, specifically starting with being concerned for hi-pot and ground bond testers, and electrical safety testers. Would also be interested in knowing the difference between the two calibrations for simple measurement equipment like micrometers and calipers. Is there a different, does ISO 17025 only certify the lab performing the calibration? Is 17025 calibration required for medical device companies?

 

[yodon]

I think you're conflating 17025 with calibration. 17025 is a management system standard for test and calibration to which you can get certified for a particular scope. Indeed, many calibration service providers have 17025 certification. Just because a cal lab is certified to 17025 does not make them appropriate for ALL calibration activities - you need to check the scope of their certification.

13485 requires calibration to be done against "measurement standards traceable to international or national measurement standards..." Often, calibrated equipment is calibrated against NIST standards. If your team has such standards (and have the necessary competence to perform calibration) then you can certainly perform calibration internally.

17025 is not required for medical device companies. Even most large companies that do a lot of calibration internally don't pursue 17025.

 

[AllTheThings]

The difference between "NIST" (a calibration traceable to a National Metrology Institute) and ISO-17025 is as yodon said, a management system accreditation for the calibration lab itself.

When you use an accredited calibration lab, you are getting assurance of the following:
* The calibration was traceable, including the uncertainties. This is often neglected by non accredited labs.
* The lab performing the calibration has been evaluated as competent to perform that calibration
* The calibration is conducted according to recognized standards or methods, under controlled conditions.
* The results have been reported to you with all information required to evaluate the suitability of the calibration with respect to your processes AND the uncertainties, if you ask. This is important if you are intending to flow down measurement uncertainty into your design or manufacturing processes.

For your purposes, you do not have to be ISO-17025 accredited. But selecting calibration labs that are accredited gives you significantly better assurance that a calibration is valid than going to someone claiming "NIST traceable". The FDA encourages ISO-17025 calibrations on a voluntary basis, considering it a best practice. It is referenced in numerous places, including here: Accreditation Scheme for Conformity Assessment (ASCA)

Now, the risk to you of using a non-accredited calibration lab (Note: 'non-accredited' cals from an accredited lab are typically OK) comes in section 7.5.9 and 7.6. If a cal lab is NOT accredited, and you use them, your 13485 auditor would be well justified in asking you to prove traceability and calibration. Are you prepared to audit a non-accredited cal supplier with respect to traceability? Do you have the staff with the skillsets to do that?

Calibration is roughly defined as a relation between two values with measurement uncertainty declared. Are you prepared to audit a non-accredited calibration supplier with respect to their measurement uncertainties?

Using a 17025 accredited cal lab obviates the need for auditing your cal supplier with respect to the 13485 requirement in section 7.6a, and relieves you of some recordskeeping that would otherwise be required under 7.5.9.1.