Patent ID: 6054852
Filing Date: 2000-04-25
Classification: G01R

Abstract:
A method of obtaining a magnetic field output signal having a frequency corresponding to the amplitude of a local magnetic field comprising:operating a self-oscillating magnetometer cell comprising a sensor, an amplifier and a voltage controlled phase shift circuit as a voltage-controlled oscillator;applying an output signal from said self-oscillating magnetometer cell to a high-frequency coil of a reference absorption cell in said local magnetic field operating on a resonance frequency having a narrow resonance line;generating a control signal representing the deviation of said resonance frequency from the frequency of said self-oscillating magnetometer cell;applying said control signal to said voltage-controlled phase shift circuit of said self-oscillating magnetometer cell such that a frequency shift is induced within said self-oscillating magnetometer cell that is proportional to the phase shift in said voltage-controlled phase shift circuit; andderiving said magnetic field output signal from said self-oscillating magnetometer cell.