When testing the properties of a material or component, a range of options are available for examining, reporting and tracking tensile data.

CALYPSO takes characteristics from a part drawing - dimensions, position tolerances and form errors - to create objects to build a measurement plan.

Confidence intervals show the range of values we can be fairly, well, confident, that our true value lies in, and they are very important to any quality practitioner. I could be 95% confident the volume of a can of soup will be 390-410 ml. I could be 99% confident under 2% of the products in my batch defective.

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. 

I offered some comments that relate to gaging problems in the last column but thought it would be worth giving measuring instruments the same treatment.

Air gaging has many advantages as an inspection method. It is quick and easy to use, and requires little skill on the part of the operator.

Gage manufacturers and calibration laboratories often find themselves in this minefield. New gages or instruments are supplied or calibrated and immediately returned by the customer because they aren’t correct.

I hate paperwork. In fact, I think the only redeeming quality most of it has is the fact that it is combustible and therefore great for starting fires in my fireplace.

Manufacturers are measuring tool tolerances in microns, finishes are highly polished and possibly diamond coated, making contactless inspection the only acceptable method.

Last year at this time I wrote a column in which I criticized the practice of having calibration labs make acceptance decisions in their reports.