ISSN:
1572-9567
Keywords:
density
;
high pressures
;
high teperaturm syringe pumps
;
vibrating U-tube
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract A vibrating U-tube apparatus has been developed for determining the densities of pure fluids and fluid mixtures at 10-200 MPa and 323-773 K. Measured parameters areP,T, andr (period of vibration). Fluids are injected into the U-tube at constantP andT. Three or more reference fluids are used to calibrate the response of the instrument. Fluid mixtures are produced by pumping pure fluids into T-junctions on the upstream side of the U-tube using high accuracy syringe pumps. An automated syringe pump is used to maintainP at setpoint ±0.01 MPa.T is controlled to ±0.01 K using a closed-loop, electronic signal amplification/feedback system. For mixtures, a statistically significant number of measurements of r are obtained to account for the effects of small heterogeneities in fluid composition (generally 〈0.005X;). Typically, density data for 15 fluids can be obtained in a 6- to 8-h period. Considering all of the potential sources of error in the experimentation, conservative estimates of uncertainty are as follows:P, ±0.02 MPa;T, ±0.05 K;p (pure fluids), ±0.0005g.cm−3; andp (fluid mixtures), ±0.0005-0.0010g-cm−3.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01448220
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