A gamma-level portable ring-core magnetometer

Using a ring-core sensor and a bridge-type peak detector, a compact low-power consumption fluxgate magnetometer of gamma-level sensitivity has been designed which uses commercial tape-wound cores. The magnetometer is of the unbalanced type as contrasted to the 2nd-harmonic type and has a total power consumption of 44 mW with an output sensitivity in excess of 0.004 volts per gamma.