Evaluation of Analog Interface for Dosimetry Temperature Probes

Measuring temperature in specimens being heated by electromagnetic energy requires the use of special probes. The temperature probes must be specially designed to minimize electromagnetic field perturbations. Several types of non-perturbing temperature measurement probes have been investigated and developed. Many employ optical fibers rather than electrical conductors to avoid the electromagnetic absorption and reflection effects. Other probes use very high lead resistances and small enclosed loop areas to reduce electromagnetic interactions. Non-perturbing temperature measurements based on thermographic techniques or measuring the viscosity of a fluid have also been developed. The probes used in this investigation are in widespread usage in research institutes and are thermistor based sensors with very high resistance leadss. These are very similar to those described by R. R. Bowman (IEEE Trans. Microwave Theory Tech MTT 24:43-45, 1976). Although the probes are commercially available, an interface is required to standard laboratory computers. This effort develops an interface between the non-perturbing temperature probes and a IBM PC compatible computer using commercially available components.