Verification of Equipment per ISO17025, Clause 6.4.4

[Testing Ryan]

I wanted to see what some of you are doing to meet the requirements of ISO17025, Clause 6.4.4, for equipment returning from an outside calibration lab. Besides reviewing the cal cert and inspecting for any physical damage, is a functional check required for the incoming equipment?

6.4.4 The laboratory shall verify that equipment conforms to specified requirements before being placed or returned into service.

 

[dwperron]

Back in my third party days we worked out a set of checklists for when we did 17025 accredited onsite visits. There was a checklist for each standard we took with us, listing some test points for appropriate functions and ranges. We would check the equipment prior to leaving the lab, and again when we returned. This fulfilled the 17025 requirement, and gave us confidence that the equipment was satisfactory for the onsite event.

For equipment returning from outside calibration we used the same process. That way we knew it was good before it left (or if it wasn't good we could start investigating possible negative impacts) and it was good when we got it back.

 

[Benjamin Weber]

Cl. 6.4.4 is quite a general requirement regarding all kinds of equipment. In the case of externally calibrated measurement equipment I would additionally consider cl. 6.6.2 c).

In our test lab we have the following process for externally calibrated equipment:
- We have detailled calibration specifications for every single equipment containing for example measurement ranges, test points and important: tolerances.
- After retrieval of the equipment we do the conformity assessment internally based on the reported measurement values and deviations (compare our specifications with the reported values in the calibration certificat). And of cource we do functional checks etc.

Why do we not just accept the conformity assessment from the calibration lab? We experienced some problems in the past, when we relied upon the external conformity assessment. For example the test points requested by us were not used.

 

[SeanN]

We would check the equipment prior to leaving the lab, and again when we returned. This fulfilled the 17025 requirement, and gave us confidence that the equipment was satisfactory for the onsite event.

- What is the reason behind checking the equipment prior to leaving the lab? The calib. frequency should make sure that the equipment is still "good".
- If your lab is capable and qualified to check/cal why do you need to send them to an external service? Normally, you send the ref. equipment (such as ref thermometers, weights...) to external service because you can't do it yourself. Can you really check the technical parameters when they return? Even if you can calibrate the equipment but you are not specialized in that type, you would unlikely pick an external service that is also not an expert, right?

 

[dwperron]

- What is the reason behind checking the equipment prior to leaving the lab? Because moving the equipment is a main cause of causing calibration failures in an instrument. If you send it out for calibration and they find it OOT you now need to determine when that happened. Checking before you ship a unit gives you an opportunity to prove it worked before it was shipped.

The calib. frequency should make sure that the equipment is still "good". This is a myth. The calibration interval is an estimate of how long the unit will typically remain in tolerance, it doesn't "make sure that the equipment is still "good""

- If your lab is capable and qualified to check/cal why do you need to send them to an external service? Normally, you send the ref. equipment (such as ref thermometers, weights...) to external service because you can't do it yourself. You need to send some standards to other calibration sources in order to maintain traceability to National labs. If nothing leaves your lab you lose traceability.

Can you really check the technical parameters when they return? Even if you can calibrate the equipment but you are not specialized in that type, you would unlikely pick an external service that is also not an expert, right? In reality, even a good lab is not able to verify the accuracy of all standards upon return from calibration. Reality dictates that you must make the best effort possible to validate the calibration results. You use the best tools you have to make the best measurements you can. Here is where checking before and after sending them out for calibration is a powerful tool - you can see if anything drifted. If the results remain the same and it passes calibration then you can have confidence the equipment is OK.

 

[Testing Ryan]

Thanks everyone for the feedback. The discussion has been very helpful.