Precise certification of the temperature measuring system of the original Koesters interferometer and ways of its improvement

New Studies of Thermal Evolution Process

“…The use of the adapters gave the possibility to reduce drastically the temperature gradients in the contacts between the surfaces of the GB and the adapters, so that it opened the opportunity to realize the calibration of the self-heating of the thermometers on the surface of a particular material with a few μK uncertainty [9,10]. In our experiments, the calibration of the measuring channels 1 and 2 was realized inside the Kōsters interferometer equipped with its own temperature stabilizing system, so that temperature gradients in the gauge block (on whose surface the calibrations were performed) were an order of magnitude smaller than in case of our Dewar system.…”

“…These calibrations were realized using a precision Rosemount (USA) standard 25-Ohm platinum resistance thermometer (SPRT), which was also equipped by a special copper adapter that was in contact with the GB surface. We used the Mi-bridge, which was programmed to change the current in the PRT), and used the procedure of calibration described in [9,10]. As a result, we had two thermistor channels that were able to measure the temperature difference of the GB surface in the close vicinity of the adapters of our thermistors with a few µK uncertainty.…”