Simple nonperturbing temperature probe for microwave/radio frequency dosimetry

We present a simple readout device that fills the void produced by the gradual disappearance of the Vitck model 101 Electrothermia Monitor. The new device uses commercially available probes that are similar to Bowman's (IEEE Trans Microwave Theory Tech MTT-24:43-45, 1976) original design. As described, the device covers the range of 7 degrees to 45 degrees C with an accuracy and resolution of better than 0.1 degree C throughout. The digital readout (3 1/2 digits) is proportional to the thermistor resistance in the tip of the probe; it is converted to temperature through a formula or printed table. Outdoor dosimetric comparisons between the new and Vitek devices were conducted. Results showed no significant difference in the calculated specific absorption rates (SARs); moreover, variance was lower in the data collected from the new device.