11
IN CASE OF IRREGULAR CYLINDERS IS IT POSSIBLE TO
MEASURE THEM WITH THE ARCHIMEDE HR?
It is possible to measure an irregular cylinder only by repeating the measurement
on different arcs of the same cylinder, to obtain the value of the Average Diameter.
It is impossible to perform a single-shot measurement to obtain an accurate
diameter value.
In the picture above, a theoretical cylinder is shown with two flat surfaces, that make
it a cylinder with a polygonal deformation. In this case, the value of the diameter
calculated by Archimede in the position shown in the picture, does not coincide with any
comparative measurement obtained from two points measuring instrument as a caliper
or an outside micrometer.
In fact, when the measure of the cylinder shown above is taken with a caliper, the
diameter is obtained the diameter taking into account only one of the two flattened
areas, because the measurement is made taking the distance on two diametrically
opposite points.
With Archimede instead it is possible to determine the measure of the average diameter
(inscribed) of the circumference passing through both flattened areas, as shown in the
picture.
Archimede returns only and always the diameter measurement of circles, while a two
points measuring device as a caliper, an outside micrometer or a two points bore gauge,
returns only the measurement of lengths.
The measurements taken at two points and those taken with Archimede may be
coincident only if the measured piece has a limited form error, as indicated in Tab.1.
