“…More volatile minor impurities could drastically affect the result. The differential thermal analyzer technique (Hamaker and Kerlinger, 1969;Eggertsen et al, 1969;Blaine and Levy, 1974) could measure vapor pressures to 10~7 torr. This method suffers from the drawback that the material under study is heated above its melting point and the vapor pressure is extrapolated below the melting point.…”