Although it is widely known that manufacturers of quality parts re-quire the use of coordinate measuring machines (CMMs) to ensure part accuracy, it is not as clearly understood that a calibrated CMM is not the same as a certified CMM. Treating the two processes interchangeably is a common--and someArial costly--mistake.
The difference between calibration and certification is very simple, but a lot of people don't understand it. Certification simply involves verifying the performance accuracy of a CMM at a given point in time. Then, if you find that the machine is not performing accurately enough for your application, recalibration is necessary. Recalibration involves making adjustments to the CMM and doing whatever is necessary to restore the machine to its original performance accuracy parameters.