Patent ID: 6417660
Filing Date: 2002-07-09
Classification: G01R

Abstract:
A method for obtaining a temperature-coefficient-compensated output signal in an optical sensor for measuring a periodically fluctuating electrical and/or magnetic field strength, comprising the steps of:sending light that can be influenced by a field strength through the periodically fluctuating field strength, producing two intensity signals from said light that has been sent through and influenced in said sending step, said two intensity signals being separate from one another and being of intensities containing intensity portions that fluctuate in chronologically periodic fashion in phase opposition to one another dependent on the periodically fluctuating field strength, and deriving a quantity from the two intensity signals said quantity corresponding to a quotient of a difference of intensities of the two intensity signals and a sum of said intensities of said two intensity signals said quantity including a direct portion and a periodically fluctuating alternating portion with a root-mean-square value obtaining a temperature-coefficient-compensated output signal by formation of a quotient of the periodically fluctuating alternating portion of said quantity and a function determined by a calibration measurement of the direct portion and of a root-mean-square value of the periodically fluctuating alternating portion of said quantity.