Novel laser flash technique to measure thermal effusivity of highly viscous liquids at high temperature

A simple but useful experimental technique featuring a novel configuration for a sample cell, high-speed infrared detector and a heating pulse laser has been developed to obtain reliable thermal effusivity of a highly viscous liquid at high temperature. The sample is melted in a platinum crucible and heated to the desired temperature. A single laser pulse is flashed on the bottom of the platinum crucible and the infrared ray irradiated from the same bottom surface is measured to obtain the temperature decay, from which the thermal effusivity of the liquid sample can be estimated. The usefulness and validity of this new laser flash technique were successfully confirmed by measuring the thermal effusivity of silicate glass in the temperature range between 773 and 1673 K. (C) 2001 American Institute of Physics.