BIBLIOS

Document type
Journal articles

Document subtype
Full paper

Title
Absolute steady-state thermal conductivity measurements by use of a transient hot-wire system

Participants in the publication
H.M. Roder (Author)
R.A. Perkins (Author)
A. Laesecke (Author)
C.A.N. de Castro (Author)
Dep. Química e Bioquímica
CQE

Summary
A transient hot-wire apparatus was used to measure the thermal conductivity of argon with both steady-state and transient methods. The effects of wire diameter, eccentricity of the wire in the cavity, axial conduction, and natural convection were accounted for in the analysis of the steady-state measurements. Based on measurements on argon, the relative uncertainty at the 95 % level of confidence of the new steady-state measurements is 2 % at low densities. Using the same hot wires, the relative uncertainty of the transient measurements is 1 % at the 95 % level of confidence. This is the first report of thermal conductivity measurements made by two different methods in the same apparatus. The steady-state method is shown to complement normal transient measurements at low densities, particularly for fluids\nwhere the thermophysical properties at low densities are not known with high accuracy.


Institution
FACULDADE DE CIÊNCIAS DA UNIVERSIDADE DE LISBOA

Where published
Journal of Research of the National Institute of Standards and Technology

Publication Identifiers

Publisher
National Institute of Standards and Technology (NIST)



Document Identifiers
DOI - https://doi.org/10.6028/jres.105.028
URL - http://dx.doi.org/10.6028/jres.105.028

Keywords
argon convection dilute gas hot wire instrument steady state thermal conductivity transient

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