TRACEABILITY OF THREAD RING CALIBRATION ON A CO-ORDINATE MEASURING MACHINE
Abstract
Thread rings are widely used for screw thread gauging. They can be calibrated on 1D measurement machines with ball probes, by using control thread plug gauges, or on three co-ordinate measurement machines (CMMs) by using special probes and software. The last method is used in our laboratory for calibrating rings from 5 to 300 mm. The calibration procedure based on this method was accredited by RvA which is EAL member and signatory or MRA. The basic problem by creating the procedure was traceability of the CMM measurement. Since the CMM is used as a calibration device in this case, simple periodical performance tests are not sufficient for assuring traceability at a certain level of uncertainty. Therefore, a special substitution method was involved. Reference standards in the substitution procedure are gauge rings, which are calibrated on 1D measurement instrument by using laser interferometer as the linear measurement system. Reference values are set by combination of gauge blocks. Basic approaches are presented in the paper.
Event details
- Event
- XVI IMEKO World Congress
- Place
- Vienna, AUSTRIA
- Time
- 25 September 2000 - 28 September 2000