Multiple Measurement Techniques for Coordinate Metrology

Reversal and multiple measurement techniques have been used in dimensional metrology [1]. The reversal technique in straightness measurement is very common method. The techniques are able to reduce the errors which come from a measuring instrument and compensate the errors automatically. The techniques are available to CMM measurements. For ball-plate calibration, the reversal technique is used in National Metrology Institutes (NMIs). The technique automatically eliminates the geometrical errors of a CMM, for example, straightness, perpendicular and angle (pitch, yaw and roll). The multiple measurement technique is used for measuring symmetrical features as cylinders [2]. We tried to apply the technique for the pitch measurement of a gear. In this paper, we describe the multiple measurement techniques for coordinate metrology, especially, application to gear measurement.