Apparatus for determination of pressure-density-temperature relations and specific heats of hydrogen to 350 atmospheres at temperatures above 14°K.

Abstract

M ethod a nd appa ratu s a re designed for more rapid determination of accun,te, closelyspaced , PVT a nd specifi c h eat data t ha n realized by prev ious procedures . A sequence of pressure-temperature observations at nearly co nstant d ensity is made by a modifi ed R eichsa nsta lt method. T emperatures of t h e esse nt ialJy adiabatic piezometer ar e regulated by electri c b eating under co nt rol of t he measurin g thermom eter. In st rum ents fo r meas uremc nt a nd cont rol are integrated \yit.h a high-pressure calori meter for co mpressed li qu id a nd flu id. Calo rim etri c experim entaLion is acceleraLed by use of a n elect ron ic battery for t he calorim etric heal suppl y a nd of a d-c pOIVe r reg ul ator develo ped for a uto m atic shield co nt rol. D etails a rc given of t he PVT ca librat ions, a djust me nl co mpuLations, a nd co mpa ri so ns wi t h indepe ndent data.