Four kinds of thermometry are available at the High B/T Facility: capacitance, melting curve, Pt NMR, and vibrating wire thermometry.
A capacitance thermometer is used for ultra-low temperature measurements when large variations in magnetic field are required for an experiment and conventional thermometry is not suitable because of the field dependence of those thermometers.
Pt NMR thermometry, as used in the High B/T Facility, relies on the paramagnetism of the Pt nuclear spins, which obey Curie's law with the NMR free-induction amplitude inversely proportional to temperature.
The vibrating wire thermometer measures the viscosity of the superfluid medium in which it vibrates. The temperature is determined form the known temperature dependence of the viscosity.