Abstract
The cyclic heat method consists of two kinds of determining ways of thermal diffusivity of thermal insulations. One is the way to measure a time lag of the phase of heat waves conducting in the test specimen, the other is to measure the amplitude decay of a heat wave. We have designed a thermal diffusivity test apparatus by the cyclic heat method, and tested under atmospheric conditions and evacuated conditions. This apparatus is able to test thermal diffusivity at temperature range from 100 to 1000 °C. We have determined thermal conductivity values of thermal insulations by multiplying thermal diffusivity, specific heat, and bulk density. The thermal conductivity values of thermal insulations measured by this apparatus are good agreement with the values by the thermal conductivity test apparatus by the Guarded Hot Plate(GHP) method.
