The modified Rankine balance: A highly efficient, low-cost method to measure low-temperature magnetic susceptibility in rock samples

In this article, we present a method to measure the relative changes in the magnetic susceptibility of rock samples in the low-temperature range (–200 °C to +20 °C). The method differs from other experimental methods currently used in that it requires—in contrast to ac bridges, the most widely used devices—very little sophisticated laboratory equipment: A high-precision laboratory balance, a Pt-100 thermoelement and a computer with standard input/output interface and analog/digital processing capabilities, as well as a few rare earth magnets, are the only devices needed in addition to standard laboratory equipment. A Dewar container and a few plexiglass panes can either be handcrafted in the workshops of any larger research institute or are commercially available at little cost. The results of our measurements reveal that the temperature-varying magnetic properties of rock samples can be reliably observed