Investigations of the low- and high-frequency response of 3\#om\-sensors used in dynamic heat capacity measurements

The 3\#om\ sensor is a thin metal strip which is evaporated onto a substrate. The sample is probed by periodic diffusive thermal waves of frequency 2\#om\ emitted from the strip. The heater temperature measured at frequency 3\#om\ yields the dynamic heat capacity. The validity of a one-dimensional h...

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Bibliographic Details
Published in:Measurement science & technology 1998-11, Vol.9 (11), p.1873-1885
Main Authors: Jonsson, U G, Andersson, O
Format: Article
Language:English
Online Access:Get full text
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Summary:The 3\#om\ sensor is a thin metal strip which is evaporated onto a substrate. The sample is probed by periodic diffusive thermal waves of frequency 2\#om\ emitted from the strip. The heater temperature measured at frequency 3\#om\ yields the dynamic heat capacity. The validity of a one-dimensional heat flow model, assuming an infinitely thin heater, has been studied using a finite element modelling (FEM) technique as well as experiments. To obtain results within 1% of the theory, FEM shows that the ratio between the heater width and the heat wave penetration depth must be greater than 30, which sets a low-frequency limit for the model. At high frequencies, the finite thickness of the heater causes a deviation from the model. (Original abstract - amended)
ISSN:0957-0233