Scanning in situ self-calibration method for the two-probe method of straightness measurement

When using the software datum to exceed the accuracy limit by the hardware datum of surface profile measurement, the calibration accuracy of the sensor becomes an important factor. A sensor self-calibration method is presented in this paper. This method is specifically developed for in situ calibration of the sensors used in the two-probe method for construction of software datum of surface profile measurement, in which two displacement probes are employed to separate the surface profile from the scanning error motion. This method has the advantage of being insensitive to the sensor setting error and the repeatability of the scanning reference. Principle of the in situ self-calibration method and results of measurement experiment are described.