PMEL Forum

General => General Discussion => Topic started by: briansalomon on 04-25-2017 -- 13:23:36

Title: Substitution of Standards
Post by: briansalomon on 04-25-2017 -- 13:23:36
I'm primarily using GIDEP procedures and have a question regarding substitution of standards.

If the procedure does not indicate equivalent or better standards can be substituted and lists no sub item for a standard I appear to have no leeway regarding substitution.

I don't see anything in ISO 17025 to address this.

Has anyone found a solution for this?
Title: Re: Substitution of Standards
Post by: griff61 on 04-25-2017 -- 13:32:47
In every instance that I have been audited on equipment, if you can prove (and show your work) that your substitution is either equivalent to, or better than the standard listed, there has not been a problem, but you need to know what you're talking about. Not every lab is going to have the model they list, more likely not.
Title: Re: Substitution of Standards
Post by: NC-Cals on 04-25-2017 -- 13:49:19
Your ISO scope is your best uncertainty. If you replace a standard, even if it is less accurate, but you have calculated your uncertainties correctly, then there is no problem. Make sure documentation and procedures are sound and your not overstating your uncertainties. If you substitute a standard that is more accurate than your budget equipment, you can only report the uncertainty stated on your scope. For example, our electronic budgets are based on a Fluke 5500A.  If I buy a 5522A, I can't start reporting uncertainties based in its accuracy until the scope is approved by my accreditation body.
Title: Re: Substitution of Standards
Post by: BamaKid on 04-25-2017 -- 14:08:19
Another way to be able to do this is to ensure that you have department standard operating procedures that address your substitution rules or protocol in these situations. This is valuable not only for having objective evidence for auditors that there is a written process, but you will ensure standardization within your work group for any technician to behave in this situation.

Working in a FDA regulated environment, you learn to address areas that are not defined specifically in the FDA QSRs within your own SOPs or in a quality manual. In other words, you define how you operate and provide the rationale.
Title: Re: Substitution of Standards
Post by: briansalomon on 04-25-2017 -- 17:29:29
I had thought the SOP was key but wanted to know what you guys were doing.

Thanks for the feedback.
Title: Re: Substitution of Standards
Post by: Hawaii596 on 04-27-2017 -- 09:37:53
Minimum Use Specifications (MUS). In Navy procedures in GIDEP, I believe they so state. Our policy is that anything that meets the MUS needed for the calibration can be used.
Title: Re: Substitution of Standards
Post by: briansalomon on 04-27-2017 -- 10:53:37
A bit off-topic but what do you guys like for an AC high voltage probe?

I'm looking for precision up to 10KV@60Hz
Title: Re: Substitution of Standards
Post by: Hawaii596 on 04-27-2017 -- 10:58:40
Ross Engineering.
Title: Re: Substitution of Standards
Post by: Irv1n on 04-30-2017 -- 03:24:28
We use Vitrek 4700 with probe up to 110 kV
Title: Re: Substitution of Standards
Post by: flew-da-coup on 05-01-2017 -- 08:12:48
I am a big fan of Ross Engineering. They make the best dividers.
Title: Re: Substitution of Standards
Post by: briansalomon on 05-01-2017 -- 09:43:26
They look good. I'm submitting a req for a VD15 from this morning.