Some Low Temperature Thermometry Observations

The temperature calibration on annealed Chromel-P/Au–Fe thermocouples has been extended from 1.3 to 0.55 K. Temperature calibration tables on annealed copper/Au–Fe thermocouples are presented. Electromotive force constants representing the potentials from annealed Au–Fe thermocouples between liquid helium and liquid nitrogen temperature references and between liquid helium and ice temperature references have been measured. Through the use of these emf constants, the calibration tables have been shifted and may be used either with an ice bath or liquid nitrogen temperature reference bath. Temperature calibrations on small platinum sensors manufactured by Minco Products, Inc. are given.