Patent ID: 6586943
Filing Date: 2003-07-01
Classification: G01D,G01L

Abstract:
A sensor signal processing apparatus comprising:sensor means whose characteristics change in accordance with a change in physical quantity to be measured, wherein said sensor means comprises two sensor elements; power supply means for supplying powers of two systems having different polarities to said sensor means; switching means, connected between said power supply means and said sensor means, for sequentially switching four combinations of connections between powers of the two systems from said power supply means and said sensor elements while preventing mixing of powers of the two systems such that first to fourth signals are output from the sensor elements, wherein each of the first to fourth signals correspond to one of the four combinations of connections of said switching means; and arithmetic means for obtaining a first difference between the first and second signals output from said sensor elements, and a second difference between the third and fourth signals output from said sensor elements, and then obtains a ratio between the first and second differences to substantially eliminate at least one of a circuit-based error and an element-based error.