Measurement of B versus H of Alumel from 25 to 180 °C

Abstract

The relationship between the magnetic induction B and the magnetic field H in Alumel was measured by the ring method for temperatures T between 25 and 180 °C. These data were needed to correct for large temperature measurement errors that occurred when Chromel‐vs‐Alumel thermocouples were used in a magnetic field. Through application of the Weiss equation, the saturation value of the intrinsic magnetic induction B_s was calculated as a function of T from the experimental B‐vs‐T data. Weiss’s method was used to determine the Curie temperature of Alumel, T_c?152 °C, from a plot of B²_s versus T near T_c. The experimental values of B_s versus T were in good agreement with those obtained from the Brillouin function with quantum number J=1/2.