If your company intends on using an outside source for your calibration work, sooner or later a choice has to be made from a short list of candidates.

A friend in the industry contacted me recently for suggestions on dealing with a request from a customer of their calibration service requesting the results of vision tests on their lab people.

Before I get into hand-to-hand combat on this gentle reader, I thought it might be helpful to explain a few things about what uncertainty is, and what it is not.

Regular readers of my rants on these pages will know that since I’m a pretty simple guy, it doesn’t take much to get me excited or amazed.

Calibrating adjustable thread ring gages can get a bit sticky on occasion due to customer assumptions versus the requirements of ISO 17025.

I regularly take shots at quality auditors for some of their antics but thought that, in the interest of fairness, it was time to turn my sights on issuers of calibration reports for some of their antics.

Most threaded products such as fasteners are verified using fixed limit gages when their ability to assemble with mating parts is of primary concern.

Nothing makes life easier than having a ‘master’ for the dimension(s) you have to measure. But a simple request for one with a dimension attached to it, for example, is not enough information to get something that will do what you want it to.

A lot of people play fast and loose with the frequency of calibration on their gages, masters and instruments.