Reference Sphere… some facts

It is very important that the correct reference sphere is used, and that its latest calibrated size is entered into Calypso.  It is also essential that the stylus tip and calibration artifacts are scrupulously clean. The smallest amount of dust can lead to an incorrect probe calibration (i.e., the measurement results can have significant errors). 

The following  illustrates a typical Calibration Certificate of a Reference Sphere. 

SOME FACTS:

• To be able to calibrate the pre-travel effects, the radius of the reference sphere needs to be known precisely, as does the separation between the center of the reference sphere and the center of the part.
• The reference sphere is used for probe qualification
• The reference sphere MUST be checked for wear/damage/rust/misuse, etc, but normally it is solid built and does not wear out easily
• Perhaps it should be re-calibrated if someone drops it or hits while loading the part
• The sphere is used to check the actual diameter of the styli and inter-relation to other styli (probing system)