I have received a couple of emails from readers recently concerning what does or does not have to be calibrated within a quality system. In both cases, the companies already have a program in place to ensure their measuring equipment, masters, etc., are calibrated on a regular basis but an odd item has popped up leading to debate within the company on whether that odd item has to be included in their calibration program as well.
I received an email from a reader with a question about different kinds of reports and certificates dealing with calibration—a subject that I comment on from time to time.
There’s no question about this column. I accept the blame for what appears in this monthly effort for better or worse. This column is all about the standards I often refer to in my rants. I frequently encounter folks who question the information these standards contain and sometimes the question is valid but there are ways to challenge or change technical details within them.
I’ve commented on this subject from time to time but thought I’d have another go at it since the questions never seem to go away. I’m referring to the language used in our day-to-day work in measurement and calibration.
You’ve made the threaded parts and are confident they are okay because you’ve checked them with your gages. Then you get the call from the customer advising you that their gages have rejected the parts and they are demanding re-work or replacements ASAP.
In recent columns I’ve commented on information requests accompanying calibration orders. Some of these are common and effective but some are not. Occasionally, they are brought about due to their inclusion in one standard or another but are misrepresented. In some cases, the standard they are from relates to in-house systems rather than calibration activities by outside parties.
I took a cursory look at this subject in a recent column but with the increasing number of companies expecting their calibration sources to make such decisions on their behalf, I thought a little more detail was in order.
When the parts are rejected or the gages or instruments are giving dodgy answers the red flag goes up and panic usually ensues. Everyone involved defends their turf, talent or toys which is normal but rarely answers the question of what’s gone wrong.
A few customers are requesting that reports show the actual lab humidity during calibration of their equipment. I realize that this can be a critical consideration for some types of calibration but when it comes to fixed limit gages, I have never heard the rationale for such a request other than it’s what their customer expects.
Calibration reports are supposed to be clear and concise so the reader can understand the details. In fact, the ISO 17025 standard has a section that deals with this topic in specific terms so it would seem there should be no room for misinterpretation.