Fast Multichannel Precision Thermometer

This paper describes a fast multichannel precision thermometer working in a temperature range from -50degC to +40degC. Thermistors are used as temperature sensing elements. A detailed discussion of the choice of thermistor and design of the circuitry is given. It is shown that accuracy similar to that of calibrated platinum thermometers can be achieved by calibration of thermistors. During our tests, the accuracy of the thermometer was both mathematically and experimentally analyzed in detail. The stability of 30 thermistors after six months of laboratory use was analyzed. Deviations smaller than 30 mK in the range from -50degC to+10degC were observed.