Apparatus to measure the vapor pressure of slowly decomposing compounds from 1 Pa to 105Pa.
This article describes an apparatus and method for measuring vapor pressures in the range from 1 Pa to 105Pa. Its three distinctive elements are : (1) the static pressure measurements were made with only a small temperature difference between the vapor and the condensed phase, (2) the sample was degassedin situ, and (3) the temperature range extended up to 200 °C. The apparatus was designed to measure metal-organic precursors, which often are toxic, pyrophoric, or unstable. Vapor pressures are presented for naphthalene, ferrocene, diethyl phthalate, and TEMAH (tetrakisethylmethylaminohafnium). Also presented are data for the temperature-dependent decomposition rate of TEMAH.
Sensor Science Division, National Institute of Standards and Technology Gaithersburg, Maryland, 20899-8411.
Robert F
RF
Berg