BIBLIOS

Document type
Journal articles

Document subtype
Full paper

Title
A New Instrument for the Measurement of the Thermal Conductivity of Fluids

Participants in the publication
S. G. S. Beirão (Author)
FACULDADE DE CIÊNCIAS DA UNIVERSIDADE DE LISBOA
M. L. V. Ramires (Author)
FACULDADE DE CIÊNCIAS DA UNIVERSIDADE DE LISBOA
M. Dix (Author)
IMPERIAL COLLEGE LONDON
C. A. Nieto de Castro (Author)
Dep. Química e Bioquímica
CQE

Summary
The transient hot-wire technique is at present the best technique for obtaining standard reference data for the thermal conductivity of fluids. It is an absolute technique, with a working equation and a complete set of corrections reflecting departures from the ideal model, where the principal variables are measured with a high degree of accuracy. It is possible to evaluate the uncertainty of the experimental thermal conductivity data obtained using the best metrological recommendations. The liquids proposed by IUPAC (toluene, benzene, and water) as primary standards were measured with this technique with an uncertainty of 1% or better (95% confidence level). Pure gases and gaseous mixtures were also extensively studied. It is the purpose of this paper to report on a new instrument, developed in Lisbon, for the measurement of the thermal conductivity of gases and liquids, covering temperature and pressure ranges that contain the near-critical region. The performance of the instrument for pressures up to 15 MPa was tested with gaseous argon, and measurements on dry air (Synthetic gas mixture, with molar composition certified by Linde AG, Wiesbaden, Germany, Ar – 0.00920; O2 – 0.20966; N2 – 0.78114), from room temperature to 473 K and pressures up to 10 MPa are also reported. The estimated uncertainty is 1%.


Institution
FACULDADE DE CIÊNCIAS DA UNIVERSIDADE DE LISBOA

Where published
International Journal of Thermophysics

Publication Identifiers

Publisher
Springer Science and Business Media LLC



Document Identifiers
DOI - https://doi.org/10.1007/s10765-006-0093-7
URL - http://dx.doi.org/10.1007/s10765-006-0093-7

Keywords
air argon fluids instrumentation thermal conductivity transient hot-wire technique

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