Patent ID: 6389371
Filing Date: 2002-05-14
Classification: G01L

Abstract:
A signal processing circuit of a sensor for processing an electric signal, the sensor having a sensor element for electrically detecting a change in physical amount of a workpiece and a signal output means for detecting the change of the sensor element and outputting the electric signal, the signal processing circuit comprising a processor for obtaining a reduced value P of the physical amount by calibrating a detected value k obtained by the electric signal with a transforming formula of, P=Î³Ã—(k-Î²)1+Î±Ã—(k-Î²)the processor comprising: a coefficient arithmetic section for calculating coefficients &agr;, &bgr; and &ggr; of the transforming formula by obtaining a detected value corresponding to known physical amount at three points within a measurement range of the sensor and assigning the detected value to the transforming formula; a calibration arithmetic section for obtaining the reduced value P of the physical amount by assigning the calculated coefficients &agr;, &bgr; and &ggr; and calibrating the detected value k detected in accordance with an unknown measured physical amount by the transforming formula; and a fundamental arithmetic section for conducting a calculation represented by the formula of, f=Z-WX-Ybased on predetermined arguments X, Y, Z and W input from the coefficient arithmetic section or the calibration arithmetic section and outputting a calculation result f to the one of the coefficient arithmetic section and the calibration arithmetic section from which the predetermined arguments X, Y, Z and W are output to the fundamental arithmetic section.