Good morning ladies and gentlemen. I have a query that is not PCDMIS specific but affects all of us that report to ISO Audit teams on a yearly basis. We had our 3 CMMs calibrated over a month ago and the following results were generated by the Hexagon techs. As required, the individual machines go thru a perassessment inspection to the factory specs prior to adjustment. Our Sheffield was found to be about .0006" out of factory spec tolerance for the Y-axis linear displacement test (over 2000 mm). And of course adjustments were made and the machine retested. The questions are these. First, do I need to cover my *ss to an ISO auditor over the possibility of us inspecting product with this CMM that could be deemed nonconforming because of the error prior to the calibration? Am I covered by any outside documentation to the fact that this is a common fact found in our world as one may ask, how do I know this machine is measuring to spec 3 days after the calibration? I believe GE Aviation once directed some literature on measurement uncertainty towards this. Second, do I need even present the preassessment data to an ISO auditor or just submit validation that the CMM was calibrated on such and such a date and say here's the cert saying it passed factory spec assessment? Please get back to me asap as we're getting close to that date.
Search and read up on the posts here by Hilton Roberts on CMM measurement uncertainty and process control.
Having an artifact made which contains features you regularly check, which you inspect on a daily basis, is a great way to verify your CMM accuracy/repeatability has not drastically changed since the last calibration.
Search and read up on the posts here by Hilton Roberts on CMM measurement uncertainty and process control.
Having an artifact made which contains features you regularly check, which you inspect on a daily basis, is a great way to verify your CMM accuracy/repeatability has not drastically changed since the last calibration.
