Method and apparatus for automatically adjusting the measurement range of admittance level sensors

摘要

A method for rectifying a sensor current with a synchronous demodulator, wherein the rectifying factor of the synchronous demodulator can be controlled. A control clock pulse signal of the synchronous demodulator is toggled between at least two different states, with the states corresponding to different rectifying factors. The resulting total rectifying factor of the synchronous demodulator can be selected at will by adjusting the pulse duty factor between the at least two states.