Polar angle (PA) axis definition of dimension (true position)

huangyhg

The polar angle PA and polar range PR represent the location of the feature in polar coordinates. The DEV of PA, PR is the deviation of the measured location from nominal expressed as the deviation in PA, PR. Since legacy true position reports these deviations in the current alignment, if you have aligned to the center of the considered feature, then the DEV of PA, PR would represent the deviation angle, range. Otherwise (not aligned to the center of the considered feature), the DEV of PA, PR represents the deviation of the nominal location. With FCF’s, if you are reporting in Datum reference frame alignment and the DRF is aligned to the center of the considered feature, then the DEV of PA, PR would again represent the deviation angle, range. As far as I know, PC-DMIS has behaved this way since day 1.

Fig.1 the definition of the polar angle (PA) at workplane_Z

[/url][url="http://www.dimcax.com/image/PA.JPG"]