Other Dimensions: Free Gage Calibration?
September 29, 2009
With so many gage buyers focusing on costs alone rather than what they are actually getting for their dollars, it follows that suppliers will do the same. It often becomes a situation where a gage buyer pretends to want calibration while the supplier pretends to deliver it.
This situation arises most often when new gages are purchased. The customer believes that purchased gages should automatically come with a calibration report complying with ISO 17025, ANSI Z-540 or other standards. After all, the gages had to be measured during manufacture, which is quite true. But who took those measurements?
Furthermore, those measurements do not equate to calibration done in an accredited laboratory by a technician not connected with the manufacture. In many cases, the equipment used in the laboratory is more accurate than that used on the shop floor, where the measurements made during gage manufacture are done.
Many gage suppliers have calibration facilities that are not accredited by an appropriate agency so the “reports” or “certs” they issue do not comply with any recognized standard. And more importantly, their performance capabilities have not been verified independently. Some try to skate around the issue by stating that because they are an original equipment maker, the standards allow their reports to be accepted without accreditation. Some standards do say that, but only if there is no accredited lab to do the work; these days, with fixed gages, many such facilities are able to do so.
The word free should be a red flag because nothing is free except the weather. If data is provided on this basis, the numbers are usually from the shop floor, which hardly comply with the standards, let alone good metrology.
Some suppliers suggest that a certificate of compliance is as good as a calibration report, but this is not true by any stretch of the imagination, even though some quality auditors will accept such certificates. Because most of these documents are issued at no cost, that fact alone tells you what they’re worth.
Suppliers who have an accredited laboratory often offer two options to the customer. Option one is an accredited report at a price. Option two is lower in cost, or even free, but it is not a report or certificate that meets the requirements of the standard-which explains why it is free.
Some folks with an accredited facility decorate their low-cost or free certificates with an accrediting agency logo so the reader will infer that the certificate is recognized by the accrediting agency, but that is not usually the case.
Many free certificates are works of graphic excellence not to mention literary brilliance, all of which is designed to make something of little or no value look good. While the word free should make you question what you’re getting, the word often found on these works of art is compliant. Usually it is buried in text extolling the virtues of the laboratory. The claim is made that the facility in question is “compliant” with the requirements of a list of standards provided, one or more of which usually does not apply or is obsolete.
If you have doubts about what a supplier is going to provide, ask for a copy of a similar document they have provided someone else, with the recipient’s name blacked out of course. The reason for this is so you’ll see what data-if any-will be provided. Put your sunglasses on so you won’t be dazzled by the gold seals or borders, and focus on what the document is really saying.
ISO 17025 or the ANSI Z-540 standard list what the report should say as far as basic information. If it isn’t there, it isn’t an accredited report. If there’s no measurement uncertainty listed for any data that is reported, it is not an accredited report.
The supplier should send you a copy of its scope of accreditation, on which you’ll find how good it is at whatever measurements its report or cert covers.
You pay your money now, or you pay your money later. If it’s later, it could be in the form of legal fees as you attempt to justify accepting reports or certs that did not meet any known standard. Or it could be the loss of a customer who knows his or her way around legitimate reports.