HEIDENHAIN ND 1300 OED and Crosshair Systems - Manual (Page 81)

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6
Measuring
Probing lines
A minimum of two probed points is required to measure a line. There is no practical limit to the number of
points that can be probed, and in general accuracy is increased by probing more points.
When only two points are probed, Measure Magic will correctly recognize a line and assign the correct
feature. However, when more than two points are probed, it is possible that the wrong feature type will
be assigned. If the wrong feature type is assigned, it can easily be changed by selecting the correct feature
from a menu of alternatives in the DRO window.
Best-fit algorithms are used to define lines when more than two points are probed. The line fit to the probed
data can also be changed by selecting the desired fitting algorithm from a menu in the DRO window.
Please refer to Chapter 12: Reference Materials for details regarding the fitting algorithms.
Measurement results are shown in the Feature list, View window and DRO window. The feature graphic
in the View window shows the feature and the points used to define it. Errors are shown as whiskers
connecting the probed points to the feature. The maximum errors are shown in red and are used in the
calculation of form. The DRO window shows the number of points used, the angular orientation of the
line, the coordinate location of the center of the line and the form error. When only two points are probed,
the form error is zero. When more than two points are probed, the form error is the sum of the two greatest
opposing error magnitudes.
Touch the feature type... to display the menu of alternative
types
Probed points are shown in the
View window
Probing and Measuring Features
In this example, three points are probed to measure a line