Proton Precession Magnetometer

The proton magnetometer. Schematic diagram of a period mode counting version of the instrument. The measurement resolution is established by the number of dividing stages "n" in the period counter, and the reference frequency "k" supplied by the oscillator. A-tuned amplifier, T-Schmitt trigger stage.

The relationship between the ambient field Bo and the
precession frequency fp is given by

where Yp is the gyromagnetic ratio of the proton.