By default, when you probe a part manually, PowerInspect uses automatic probe compensation to determine the direction in which compensation for the size of the probe is applied. This requires you to orientate the probe so that it is close to the normal of the feature surface. If you are unable to orientate the probe towards the feature you want to measure, you can control the direction of probe compensation by taking a fresh-air point before taking the point on the part. The way in which you use pre-touch points depends on the item you want to probe:
- For geometric features other than planes, the pre-touch point applies to the first touch-point on the feature.
- For inspection groups and planes, the pre-touch point applies to each touch-point.
To measure features using pre-touch points:
- Click Tools tab > Machine panel > Track. The Co-ordinates dialog is displayed.
- Select the
Pre-touch
button to activate pre-touch mode. The button changes to
.
- Take a point on the fresh-air side of the first touch point. This point is used to calculate the compensation vector for subsequently probed points; it is not recorded.
- Probe the features on the part. Compensation is applied along the vector from the pre-touch point to the measured point.
- When you have completed your pre-touch measurements, deselect the
Pre-touch
button to return to automatic probe compensation.