Temperature fixed points. 1: Possible devices in the range 0 to 125 C

The need for temperature fixed points in the temperature range 0 to 125 C for the calibration and calibration-checking of electronic thermometers based on thermistors, and small platinum resistance thermometers is shown. Metal, melting and freezing, cell, and organic compound triple-point cell devices are considered. The realization and maintenance of the fixed points are discussed to assess their use in the laboratory and the possibilities of operating the devices automatically. It is concluded that while metal cells may be easier to operate automatically, organic triple-point cells are easier to use in the laboratory and can be maintained for longer periods. While only one or two metals seem likely caniddates for fixed points in the range considered, there is a very large number of possible organic compounds available.