A technique has been developed that permits metals with melting points in the range 1000-1500 degrees C to be treated with hydrogen before encapsulation in quartz. The extrapolated onset temperature of melting of the metals was found to be linearly related to heating rates in the range 1 - 10 degrees C per min. The value obtained by extrapolation to a zero heating rate was used as the melting temperature measured by the DTA instrument. A plot of this temperature against the published melting temperature gave a linear relationship with a correlation coefficient of 0.9999. Measurement of the peak areas allowed calculation of the cell correction factor, which again showed a linear relationship with temperature, with a correlation coefficient of 0.9303, These metals can thus be used to calibrate thermal analysis equipment for temperature and enthalpy in this temperature range. The samples showed no loss of integrity over many melting-freezing cycles.