Journal of Microwave Power and Electromagnetic Energy (JMPEE)
TITLE	Thermistor Probe Error in an X-Band Microwave Field [PDF]
AUTHORS	R. D. McAfee, L. L. Cazenavette and H. A. Shubert 1974 9 3 177-180
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Abstract The reasonable assumption is made that a stainless steel hypodermic needle containing a thermistor does not couple with the electric field from a microwave horn antenna emitting 9.31 GHz radiation when the probe is perpendicular to the electric field vector in air or in solutions having approximately the salinity of tissue or blood. The degree of error in the measurement of temperature by the same probe in air orientated parallel to the electric field is 0.6°C. However, when used to measure temperature in 0.9% NaCl solutions the parallel thermistor probe did not interact with the microwave field in such a way as to change the temperature or to render the temperature readings inaccurate. These results provide a basis for considering that the use of metallic thermistor probes for the measurement of temperature increases produced by microwave irradiation of living tissue does not result in inaccuracies produced by probe orientation, provided the probe is below the surface of the tissue.