We have 24 CMMs, (7.10.7 SF and Global Advantage 5.7.5 on the shop floor) and a Global performance 9.12.8 in the metrology lab. The volumetric performance varies from 5 to 9 μm among the 24 machines (Hexagon calibration ASME B89.4.1b-2001), the metrology lab's CMM last calibration performance was 6.7 μm, This range of variation in the volumetric performance causes that the correlations between machines is a little doubtful, especially when the difference in the results should not be greater than 5 micrometers. What other arguments could be used in addition to the previous one to justify the purchase of a new CMM of greater precision and accuracy than the rest of the machines and take or use it as kind of master / reference CMM?
Shop floor machines, trying to correlate everything to within 5 microns? You probably wouldn't see 5 microns on the same machine with the same part if you measured the part every few hours just due to environmental factors.
+1, correlations between SF and Global machines has to be done very carefully, I have to use same parameters, sometimes the same probe and measure parts within minutes of difference.
+1, correlations between SF and Global machines has to be done very carefully, I have to use same parameters, sometimes the same probe and measure parts within minutes of difference.