We are a Calibration/Dimensional Testing Labortory. We have 7CMM's in our Laoboratory. We Design, Build checking fixtures mostly for the automotive industry, and Certify that the dimensional aspects of our products are correct using our laboratories CMM's. I'm looking for a procedure to evaluate the measurement uncertainties of our CMM's.
Things that effect our tests are:
1. Temperature of the CMM Lab;
2. Temperature of the item being checked
3. Material of item being checked
4. uncertianty of the equipment being used
Materials tested are mostly aluminum, steel, or plastic.
If yopu need more info let me know.
Thanks for your response,
Thanks for your reply. Yes, the temperature and humidity are controlled in the lab, and the test items are allowed to nornalize before prior to testing. The lab is certified by A2LA to guide 17025 but the assessor determined our uncertainties for us and we do not understand the fomula he used to do that. We ard looking for a procedure that is easy to understand so that we can determine our own uncertainties. The CMMs are calibrated annually by an outside source recognized by A2LA.