Temperature errors using multi-sensor thermocouple probes with a common constantan wire

Abstract

During the evaluation of thermal conduction errors in multi-sensor thermocouple probes in use for hyperthermia, an unexpected large temperature error occurred. When one of the sensors passed the temperature gradient between the hot and cold water bath a temperature offset occurred in the sensors further towards the tip of the probe. This effect caused by the temperature gradient over the thermocouple junction has been described earlier by Bach Anderson et al. (1984) and Dickinson (1985). However, their conclusion was that clinically this effect was of little importance because of the minor gradients in clinic, provided that the soldering/welding length of the junctions is small.