抄録
Recent years miniaturization of an industrial product was been pushed forward by the spead of mobile devices and a space-saving. Rotation accuracy of the spindle was progressive as improvement of machining accuracy was demanded. A high-precision measurement technique of rotation accuracy came to be demanded with these technical progress. However, a target such as a high precision ball or cylinder was necessary. Measurement accuracy was decided by roundness error. But the three three-point method is a measurement technique for ramoving the roundness error of the target. However, there is still some problems for practical use of three points method. A measurement error by a difference of measurement sensitivity of each sensor is one of them. This paper reports an algorithm to correct a difference of measurement sensitivity of each sensor.