Application of a Wollaston wired probe for quantitative thermal analysis

In this work, we have investigated the properties of the Wollaston wire thermal resistive probe which is frequently used for microthermal analysis. Special attention was drawn to the frequency dependence of the performance of the probe. We demonstrated that at frequencies above 5 kHz, the temperature of the Wollaston wire probe becomes increasingly insensitive to modulations of the driving current. We submerged such a probe in air and a number of liquids to measure the heat conductivities by simultaneous determination of the applied power and increase in temperature. The heat conductivities were established both by application of direct current (dc) and modulated current. The advantages and disadvantages of different techniques of thermal analysis with this type of resistive probe are discussed. A method of multifrequency analysis at a fixed location for the elimination of the effects of contact area and thermal resistance is proposed for analyses in the frequency range of 10-100 Hz. Crown Copyright (C) 2002 Published by Elsevier Science B.V. All rights reserved.