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Published on: January 24, 2014
A Small-Volume Apparatus for the Measurement of Phase Equilibria
Stephanie L Outcalt1, Byung-Chul Lee1
1National Institute of Standards and Technology, Boulder, CO 80305-3328.
Abstract:
An apparatus has been designed and constructed for the measurement of vapor-liquid equilibrium properties. The main components of the apparatus consist of an equilibrium cell and a vapor circulation pump. The cell and all of the system valves are housed inside a temperature controlled, insulated aluminum block. The temperature range of the apparatus is 260 K to 380 K to pressures of 6 MPa. The uncertainty of the temperature measurement is 0.03 K, and the uncertainty in the pressure measurement is 9.8 × 10(-4) MPa. An automated data acquisition system is used to measure temperature and pressure at equilibrium. The apparatus has been performance tested by measuring the vapor pressures of propane, butane, and a standard mixture of propane + butane.
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