The paper briefly describes a new apparatus for the measurement of the
composition and density for up to three fluid phases in equilibrium a
t elevated temperatures (to 150-degrees-C) and pressures (to 50 MPa) i
ncluding phase compositions and densities. In this brief article atten
tion is concentrated upon the measurement of composition for which two
different methods have been developed suitable for use with hydrocarb
on components of greatly different volatility.