High magnetic field corrections to resistance thermometers at low temperatures

We present a reliable method to account for the magnetoresistance of resistance sensors which are used as thermometers in many low temperature (T less than or equal to 20 K) experiments carried out in high magnetic fields (to 31 T). To apply the method, a set of isothermal magnetoresistance data, and a zero magnetic field temperature calibration are first necessary. A simple algorithm, which uses this data set, can then be applied to compute the temperature from the measured resistance at any field. The method is particularly useful for temperature dependent measurements at fixed field, or where, in cases where the temperature may change unpredictably during a change in magnetic field. We apply this method to the treatment of data in two separate experiments with the two different thermometers, RuO2 (below 1 K) and Cernox (above 1 K) sensors, respectively. (C) 1999 American Institute of Physics. [S0034-6748(99)02404-1].