Basic Study on Measurement of 2-D Surface Profile. (2nd Report: Measurement Error Analysis).

Recently, several differential methods have been developed to cancel datum errors of the scanning stages in the measurement of straightness and sectional surface profiles. Some of these methods are being extended to the case of 2-D surface profile measurements. Although datum errors are removed by the differential calculation of the sensor's outputs, some other measurement errors remain, and some new errors are introduced into the results of the measurement because more than one sensor is used to construct a differential measuring probe. In this paper, some of the measurement errors of the 2-D differential methods presented in the previous report are evaluated by analysis of the transfer function and the differential output of the software datum. Zero adjustment errors caused by misalignment of the sensors zero outputs are also analyzed, and a self-correction method for compensating zero adjustment errors is presented.