About 300 thermal constant measuring systems have been installed in the field since this system was put on the market in 1970 and are highly valued for excellent performance in various fields of application. This system was standardized by the Japanese Industrial Standards (JIS R 1611-1977) as a thermal diffusivity and specific capacity measuring system for fine ceramics. It is complete with a substrate measurement attachment for a 1-inch square sample and a stepwise heating attachment for a heterogeneous compound sample.