USGS Rock- and Paleo-magnetics Laboratory

Curie temperature balance

This is an automatic-recording magnetic balance. It was designed to permit the rapid measurement of Curie temperatures of small rock samples (maximum size approximately 0.25 cubic centimeters) or magnetic mineral separates. Saturation magnetization of the mini-samples also can be determined by measuring the variation of induced magnetization in applied fields ranging from 0 to 900 milliTesla (mT). To measure Curie temperatures, the sample is heated at a predetermined rate that is controlled by a furnace thermocouple sensor and a feedback system. Heatings may be performed in vacuum or in a controlled atmosphere at rates varying from 0.5 degrees to 30 degrees Centigrade per minute. Samples may be heated up to a maximum of 800 degrees Celsius. Four separate, tapered pole pieces are available to provide different magnetic field gradients.