US Patent 11402201 Coordinate positioning apparatus and method of operation

A method of calibrating a contact probe having a deflectable stylus and configured to provide at least one signal which is indicative of the extent of deflection of the stylus, the contact probe being mounted on a coordinate positioning machine which facilitates reorientation of the contact probe about at least one axis. The method includes: taking measurement data obtained with the contact probe positioned at a plurality of different orientations about the at least one axis; and determining from the measurement data at least one gain variation model which models any apparent variation in the gain of the at least one probe signal dependent on the orientation of the contact probe about the at least one axis.