9
IN CASE OF ELLIPTICAL CYLINDERS IS IT POSSIBLE THE MEA-
SUREMENT WITH ARCHIMEDE HR?
If the cylinder to be measured has a form error, Archimede will provide the value of the
diameter of a circumference passing through the three contact points on the cylinder
that is being measured. This could have a center not corresponding to the one of the
workpiece, but this does not mean that Archimede is returning a wrong measurement.
It is to be kept in mind that in case of elliptical cylinders (ellipses) the calculation
performed by Archimede for each measurement is related to the best fit circumference
passing by the instrument support points. This means that it is not possible to perform
a single measurement, but it is required to detect a series of measures (eg. 0°, 90°, 180°,
270°), from which obtain a value of Average Diameter.
In case it is necessary to measure a large size tube, if the shape error is high, it will not be
possible to determine a value of an average diameter of the piece, because the circularity
error of the cylinder makes it more similar to an ellipse or a polygon, that by definition
do not have geometric diameter.
