Cernox thermometer under hydrostatic pressure for enhanced temperature accuracy.

Sensors that can be used in a pressurized environment are few. Thus, it is generally considered that the accuracy of temperature measurements decreases in experiments carried out under pressure. Based on a commercially available cryogenic temperature sensor, Cernox from Lake Shore Cryotronics, Inc., we developed and tested an enclosure that enables Cernox to be directly used inside a cylindrical pressure cell, next to the specimen under investigation. To isolate the Cernox thermometer from the pressurized medium inside the pressure cell, we combined the principles of an encapsulated Pt sensor and a cylindrical clamped piston cell. The encapsulated Cernox allows for precise measurement and control of the specimen's temperature. It is also beneficial for accurately determining small changes in physical properties, such as temperature, or measuring the amount of hysteresis in the first-order phase transition. It would also be useful for accurately controlling the sample's temperature when the sample approaches the transition temperature from one side.