In 1967, Gustafsson proposed the idea of the transient plane source (TPS) method, but it was not developed until the 1990’s with the help of Gustavsson. The TPS method uses an engraved spiral nickel sensor to simultaneously administer a heat conducting current while measuring the temperature increase of the sample over the time. Transient plane source methods are popular because there is no limit to the sample size, the thermal range ...