Titre :
|
Periodisches hitzdrahtverfahren zur messung von warme und temperaturleitfahigkeit von geringen stoffmengen
|
Titre original:
|
Periodical hot-wire method for the measurement of the thermal conductivity and thermal diffusivity of small quantities
|
Auteurs :
|
A. Griesinger ;
K. Spindler ;
E. Hahne
|
Type de document :
|
article/chapitre/communication
|
Année de publication :
|
1997
|
Format :
|
p.419-425
|
Langues:
|
= Allemand
|
Catégories :
|
THERMIQUE THERMODYNAMIQUE
|
Mots-clés:
|
CONDUCTIVITE THERMIQUE
;
DIFFUSIVITE THERMIQUE
;
MESURE THERMIQUE
|
Résumé :
|
A measuring procedure for the simultaneous determination of the thermal conductivity and thermal diffusivity of small quantities is described. The procedure is suited for high-viscous fluids and for powdery material. The measuring principle is based on the transient hot-wire method. A sinusoidal alternating current flows through a thin platinum wire and heats up the wire periodically. This results in thermal waves, which penetrate into the surrounding sample. The amplitude and the phase shift of the thermal waves depend on the thermal diffusivity ''a'' and the thermal conductivity ''lambda'' of the sample. The temperature oscillation in the sample is measured by means of the platinum wire, which is simultaneously applied as a resistance thermometer. The values measured for water and glycerine correspond well to those given in literature. Results of the effective thermal conductivity and the effective thermal diffusivity of zeolite powder under pressurized hydrogen are also discussed. The advantage of this measuring procedure is that only a sample of 13 ml is needed for the test.
|
Source :
|
Heat and mass transfer, vol 32
|