Category: Transient Plane Source
Author(s): L. Halldahl
Abstract: When thermal conductivity and diffusivity are measured with the Hot Disk thermal constants analyzer, Hot Disk sensors of different designs are being used. Sensors are primarily made of nickel foil, arranged in a double spiral, sandwiched between two thin sheets of insulating material. For experiments between 30 and 450 K, the polyimide Kapton has been used as the insulating material. For experiments being performed at temperatures above 450 K, but below 1000 K, Mica can be used as an insulation. There are currently no insulation materials which can be used at temperatures above 1000 K, however research is currently being performed on this topic. When performing measurements, the sensor is usually sandwiched between two pieces of a testing sample of unknown properties, however research is being conducted to allow one side to be in contact with a sample of known properties, while the other side is in contact with an unknown.
Reference: High Temperatures - High Pressures 32, 1 (2000) 47 - 51