High temperature thermal conductivity measuring appts. for ceramic materials

摘要

The appts. includes a sealed enclosure (16) housing a horizontal base (2) covered by a bell shaped envelope (3). Both the base and the envelope have a double wall cooled by a water circuit. An inlet (5) and an outlet (6) are provided for evacuating the enclosure and filling it with a neutral gas. A sample of the material to be tested (10) is placed inside the enclosure. The sample is placed on a graphite resistor (26) resting on two conducting vertical bars fixed in the base. A graphite cap (24) covers the top surface of the sample. A thermocouple (34) is inserted into the cap to measure its temperature. A second thermocouple (14) measures the temperature at the top surface of the sample while a third one determines the temperature of the sample lower surface.