Are One-Point ISO 17025 Equipment Calibrations OK

G

George Weiss

In a world where sometimes the CERT and the accompanying Data Report document seem to be more important than the actual calibration or it’s effectiveness in actually verifying the test item’s compliance/non-compliance.

Question: Can or should a single point test of any equipment, even a multi-feature hand held meter be ever allowed? The ISO/IEC-17025:2005 seems to allow calibration provider/customer written agreements to almost any extent. Because of endless searches for cost containment and cost reductions, a commercial calibration lab could develop/offer an agreement, for ignorant customers, to perform single point calibrations on all of their supported test equipment. The development of the Ultra-Cheap-Basic-17025-Calibrations is actually happening now. I see this materializing. Should it?

Remote 17025 calibration.

A 17025 calibration sticker in the mail is next. OMG!
 
D

Duke Okes

Re: Are one-point 17025 equipment calibrations OK?

Is it possible? No doubt. Is it viable? Likely only in a very few instances where the instrument is only measuring a single point. Will someone do it? You bet! Will it work? It depends on the application. Will they get by with it? It depends on the technical knowledge and ethical standards of the organization and auditors.
 

bobdoering

Stop X-bar/R Madness!!
Trusted Information Resource
Re: Are one-point 17025 equipment calibrations OK?

It just goes to show that there are still so many people that don't understand the 'point' of calibration. I like to casually refer to them as "calibration weasels". My point to them is that if they have no interest in knowing if the gage is reading correctly, why pretend to have any interest in measuring at all? Save money on calibration, don't measure anything. Problem solved. Quality level TCE! :rolleyes:
 

AndyN

Moved On
Re: Are one-point 17025 equipment calibrations OK?

George - sorry to burst your bubble, but those organizations are alive and well!
 

bobdoering

Stop X-bar/R Madness!!
Trusted Information Resource
Re: Are one-point 17025 equipment calibrations OK?

There is one other thing more amusing than a one-point calibration - and that is a GR&R performed by the supplier at their own location...then used as the data of record at the company using the gage. :rolleyes:
 

Marc

Fully vaccinated are you?
Leader
Re: Are one-point 17025 equipment calibrations OK?

Is it possible? No doubt. Is it viable? Likely only in a very few instances where the instrument is only measuring a single point dimension. <snip>
Bingo! In those instances a single point calibration is sufficient.

NOTE: Strike-out in quoted text and substitution is mine as emphasis on the limited use of single point calibration.
 

Marc

Fully vaccinated are you?
Leader
Re: Are one-point 17025 equipment calibrations OK?

Not necessarily only attribute gages, Bob. I have seen variables gages that were used for measuring 1 dimension/unit in receiving and in-process (dedicated variables measurement devices such as calipers and micrometers cited on the control plan, as examples). In those cases only 1 point calibrations made sense financially so far as management was concerned. True, the full potential of the gage could not be realized. None the less, there was no need for anything other than measurement of a single (1) dimension/unit.

You would sort of be on target by replying that financially a fixed gage would make more sense, but this is not necessarily true. Fixed gages are not necessarily cheap. And - Calipers and certain glassware (examples) are often cheaper as "throw aways" as opposed to ongoing calibration in many cases. There are scenarios which require only 1 variable measurement to be taken where a fixed gage would be more expensive.

Potential uses of a gage does not always trump long term cost and use factors. If I have a caliper or micrometer (or whatever), and I only make one specific measurement with that measurement device, calibration over the full range of the device (or 75% of the range of the device to take into consideration potential 'long tail' linearity aspects, if you want to get into essentials) makes no sense.

Calibration experts, do correct me if I'm wrong. This is my paradigm as of this moment.
 

BradM

Leader
Admin
Well... I cannot speak on high on this one, because there are a lot of one-point calibrations occurring. Although, there is no 17025 accreditation involved.

If an instrument is used (like a constant temperature oven) at 50C, and never changes from 50C, why should it ever be checked anywhere else? Too, if there is product in there and during calibration it might affect the oven stability, what are they supposed to do with the product?

There is a difference in performing single-point calibration out of necessity, and out of laziness. Aside from laziness, the organization does not have the sufficient resources to perform a full loop calibration. And obviously, laziness and insufficient resources are not good reasons. :D

If you are performing calibrations, assure that you are meeting your customer's expectations. If you are having calibrations performed, make sure you are getting what you paid for, and getting what you need to give you the confidence you deserve in your process.:)
 

BradM

Leader
Admin
There is a very real downside to any limited calibration, though. Any device (especially portable) can (and so.... will:tg:) be used for a purpose within mfg. specifications, but outside the limited calibration. Therefore, good labeling and control should be exercised over limited calibrations (like single point calibration).

Any calibration not verifying mfg. specifications begins a risky venture that must be judiciously managed, IMHO.:)
 
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