A computer-controlled apparatus for performing pressure-composition-temperature measurements on metal hydrides with protium, deuterium, and tritium

An apparatus for measuring protium, deuterium, and tritium pressure-composi tion-temperature (PCT) thermodynamic equilibrium behavior on metal hydrides has been designed, constructed, and operated with deuterium at the Weapons Engineering Tritium Facility at Los Alamos National Laboratory. The appara tus is capable of performing PCT measurements with the three hydrogen isoto pes at a maximum pressure of 3.45 MPa, and sample temperatures in the range 25-300 degreesC. A personal computer that controls the system provides the capability for manual or automated operation. Two deuterium PCT isotherms on palladium at 51 and 70 degreesC were measured with the apparatus in the automated mode to demonstrate its operation. Comparison of the resulting is otherms with literature data showed a plateau pressure at 70 degreesC in cl ose agreement with the literature value (57.06 kPa versus literature value of 57.33 kPa). The deuterium capacity at 70 degreesC in palladium at the hi gh end of the isotherm was measured both by the PCT apparatus and by weighi ng the sample before and after the PCT measurement. The deuterium capacity determined by the PCT apparatus (D/M=0.624 at 144.52 kPa) agreed well with the value determined by the weight difference measurement (D/M=0.628, at 14 4.52 kPa). These values agreed closely with the literature value (D/M=0.629 at 144.52 kPa). (C) 2001 American Institute of Physics.