Realization of the 3He melting pressure scale, PLTS-2000

The Provisional Low Temperature Scale of 2000, PLTS-2000, which was adopted in October 2000, uses the melting pressure of He-3 to provide the basis for temperature measurement in the range from the Neel temperature of the solid, T (2000)=0.902 mK, up to 1 K. The definition and derivation of the scale has been published, and the present paper now gives guidance on the practical methods by which the melting pressures can be measured in the laboratory. Various options are described, depending on the equipment available, and the uncertainties that may be achieved are considered.