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GEM Systems Overhauser Proton Magnetometer

The Overhauser family of proton precession magnetometers utilise a radio frequency field to amplify the weak precession signal & in doing so achieve a higher order of sensitivity. This instrument is dual channel & is usually configured as a vertical gradiometer although a four channel magnetometer version exists. They can sample at up to 5Hz, adequate for about 0.3m resolution at normal walking speed with sensitivity of about 0.1nT, increasing to 0.01nT at slower rates of sampling.

These instruments have tended to be viewed as cheaper alternatives to caesium technology in the past but steady advances in technology & software have meant that although slightly cumbersome to use they present a real alternative to fluxgate technology, especially as they produce total field measurements with the inherent benefits common to caesium instruments.

Picture credit GEMSys

Manufacturer

GEM Systems, Canada

Web site

http://www.gemsys.ca