On the Temperature Resolution of Thermistors
The past fifteen years have witnessed the development of reaction calorimetry as an analytical methodology. The applicability of such techniques as thermometric enthalpy titration (TET) (1) and direct injection enthalpimetry (DIE) (2) to clinical and biochemical problems has greatly enhanced this development. All of the above mentioned techniques most commonly utilize a thermistor as the temperature sensing element. It is well known that thermistors are among the most sensitive and simple temperature transducers available. The detection limit of these devices is controversial. Recently Lampugnani and Meites (3) have reported an 0.6 µ° C limit, while Smith, Barnes, and Carr (4) and Dohner, Wachter and Simon (5) have reported a value of 3.5 (µ° C. Considerably higher values have also been reported (6). Thus an investigation was initiated into the effect of various physical factors which might influence thermistor sensitivity.
KeywordsTemperature Resolution Noise Source Voltage Noise Wheatstone Bridge Johnson Noise
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