Alternative To PT/ILC (Inter-Laboratory Comparison) Requirement



I am hoping to find someone that has done an in-house type ILC (Inter-Laboratory Comparison) to verify their results on a test are valid.
We are accredited for testing engine slings/straps. The verbiage on our Scope from our accrediting body is "proof-testing." I can not find a PT provider that has this type of artifact or another lab that has this type of testing listed on their scope.

So when we do this test - we pull the strap to a predetermined specific capacity and confirm the strap does not break. It either passes or fails, so I don't have any actual data to analyze, develop a Z-score, or anything.

Has anyone had any similar experience or even some thought on how to accomplish this?

Any help is appreciated!


Trusted Information Resource
First, check with your accrediting body to see what their policy is on in house ILC's. They will give you guidance as to what they can accept for your proficiency testing.

As for the ILC, it seems to me that you should be verifying that your pull tester and operators are adequate to the task. At a minimum you need to show that several operators can reproduce the results, and that the pull testing is accurate and repeatable. You could do that by setting a pull force and measuring the actual pull with some transducer or scale. From here you can determine what your acceptable range of results are (your accuracy requirements), and you should be able to use these results for your analysis, such as the Z score.


Trusted Information Resource
Clause 5.9.1 sub Clauses are listed as examples. ABs tend to interpret that as shall. However, the verbiage in 5.9.1 itself is the actual requirement.

That being said, your AB likely knows there may not be a PT for your testing, though the components may have some similar examples. Document the evidence that there is no PT, put together your own internal ILC, and be prepared to discuss an ILC with any competitors, as they may have the same issue if accredited or seeking accreditation.

Look at the other listed examples also. Have retained samples that can be retested perhaps.

Hope this helps.
Top Bottom