Recent developments and applications of the hot disk thermal constants analyser for measuring thermal transport properties of solids
Mattias Gustavsson, Johan S Gustavsson, Silas E Gustafsson, Lars Hälldahl
When thermal conductivity and diffusivity are measured with the hot disk thermal constants analyser, hot disk sensors or G-probes of different designs are used. The design of these sensors can be described as a double spiral etched out of a 10 μm thick metal foil sandwiched between two thin insulating sheets of an electrically insulating material. So far mostly nickel and in a few instances platinum foil have been used as the ‘sensing’ material. For experiments from 30 K up to about 450 K the polyimide Kapton with a thickness of 25 μm has been used as insulating material while for temperatures beyond 450 K and up to about 1200 K a 100 μm thick mica material is used. Attempts are presently being made also to use other insulating materials, which might further increase the temperature range of the sensors.