Calibration and Compensation of Dual Sensor System used in Ultra Precision Diameter and Form Measuring Instrument

摘要

In order to improve the accuracy of an instrument by reducing or correcting the error of a sensor system, a calibration device which can be used to trace the laser wavelength is used to calibrate the static and dynamic characteristics of dual sensor system. Based on the accurate calibration data of the sensor, the nonlinearity error and the coherence error are corrected and compensated using least-square approximation model and interpolation method. Test results indicate that the nonlinearity of each sensor can be within 0.15% in the range of ±10μm and the incoherence is less than 0.2 ％ in the range of ±5μm after corrected. Meanwhile, the cause and effect of a misalignment error between dual sensors are analyzed.