HEIDENHAIN ND 1400 - Manual (Page 74)

60 QC-300 Series User’s Guide
Probing spheres
A minimum of four probed points are required to measure a sphere.
The points can be probed in any order. After the initial four points,
there is no practical limit to the additional number of points that can
be probed, and in general accuracy is increased by probing more
points. The first three points should be probed around the equator,
and the last point at the top. Additional points can be probed any-
where on the sphere surface.
If the feature type is not interpreted correctly by Measure Magic, it can
be changed to a sphere when more than four points are probed.
Measurement results are shown in the Feature list, View screen and DRO screen. The feature graphic in
the View screen shows the feature and the points used to define it. Errors are shown as whiskers connect-
ing the probed points to the feature. The maximum errors are shown in red and are used in the calculation
of form. The View screen shows location and angular displacement (shown below), form error, the number
of points used, reference frame and the projection plane (3D). When only four points are probed, the form
error is zero. When more than four points are probed, the form error is the sum of the two greatest opposing
error magnitudes.
Points can be probed in any order
Touch the feature type... to display the menu of alternative
feature types
Probed points are shown in the
View screen