Low-temperature thermometry in high magnetic fields. V. Carbon-glass resistors

Abstract

The characteristics of carbon-glass resistance thermometers for temperatures from 2.15 to 320 K and in magnetic fields of up to 19 T are described. The results from nine thermometers made from six different batches of raw material are combined to produce mean values that may be used to correct a ’’typical’’ thermometer at 19 T to within ±0.1% in temperatures between 30 and 320 K, and to within ±1% between 2.15 and 30 K. All nine sensors show a small orientation dependence of their magnetoresistance at 77 K; two out of four tested have an experimentally significant dependence at 4.2 K. The temperature error corresponding to the magnetoresistance of a miniature precision platinum resistance thermometer at 19 T is less than for carbon-glass sensors above 77 K. New recommendations are made for the optimum use of low-temperature thermometers in high magnetic fields.