The Prehit Distance box lets you enter the value for the machine prehit distance. This value determines the distance away from the theoretical hit location on the surface where PC-DMIS starts searching for the part. The machine travels at touch speed while traversing this distance to search for the part.
If necessary, PC-DMIS can automatically change this when the software takes hits within an arc or circle.
The Edit window command line for this option reads:
PREHIT/nnn.nnnn
Where nnn.nnnn is a number value for the distance.
For an example of how Prehit Distance and Check Distance work together, see the example in the "Check Distance" topic.
The Probe Readout window shows the probe location based on the probe's center. However, the machine uses the outer diameter of the probe to drive to the surface. This means the values in the Probe Readout always show a probe radius less than what you might expect when it moves to this distance.