Direct Reading Resistance Thermometer Bridge. Part II
T. M. Dauphinee, Christine Kirby, H. Preston-Thomas · Review of Scientific Instruments · 1960
This paper presents the details of circuitry and construction for a direct reading resistance thermometer which has been built utilizing the design criteria formulated in Part I. By using any standard 25.5Ω platinum resistance thermometer as a sensing element, the bridge gives subdivision of the temperature scale to 0.001°C between −50° and +700°C with an accuracy exclusive of that of the thermometer of about ±0.001°C. Methods are described that allow for variations of thermometer constants, for autocalibration of the bridge circuit, and for maintaining constant sensitivity by variation of the thermometer current. The bridge as described has performed satisfactorily for three years and has proved to be a useful and convenient laboratory tool.