#### Circular Features

The default number of hits PC-DMIS generates on a circular feature is a system option. To change this value, access the Setup Options dialog box (Edit | Preferences | Setup), and then click the General tab. Type the new default number in the Auto Circle Hits edit box. | PC-DMIS can automatically generate hits for circles, cylinders and arcs. To do this:

1. Move the cursor close to the circumference of the feature.

2. Click the left mouse button. (The STATE icons must be set to Program Mode.) PC-DMIS will then generate equally spaced hits on the feature at the current probe depth. (See "Setup Options: General Tab" in the "Setting Your Preferences" chapter for setting the number of hits for circles.)

Follow these measurement rules for circular features.

- For an inside diameter (ID ), place the cursor just inside the feature.

- For an outside diameter (OD), place the cursor just outside the feature.

- To automatically program cylinders, take at least two sets of hits at different probe depths.

- When programming an arc, PC-DMIS will space the hits along the length of the arc.

- To measure a sphere or a cone, first set precise depth on the sphere or cone before generating any hits. See "Setting Probe Depth on a Sphere" and "Setting Probe Depth on a Cone".