A high sensitivity portable spinner magnetometer

Abstract

A field device for measuring the natural remanent magnetisation (NRM) of rocks, and using a directional thin film magnetometer, is described. By spinning a standard size sample, the direction of its NRM is determined, with a precision better than +or-3 degrees for an intensity of magnetisation of 10^-2 A m^-1. The sensitivity is about 10^-5 A m^-1. The instrument is battery operated and weighs about 10 kg. A prototype version of this spinner magnetometer, called Remanometer, was used in the summer of 1979 during a general paleomagnetic survey of the Hellenic sedimentary arc, and the results are related to illustrate the potentialities of the instrument.