Social system for production and utilization of thermophysical property data

— Measurement technology, metrological standard, standardization of measurement method, and database for thermal diffusivity by laser flash method —

Abstract

The National Metrology Institute of Japan implemented a system to supply reliable thermal diffusivity data efficiently and rapidly to society. The system was born out of R&D on technology for thermal diffusivity measurement by using a laser flash method, by establishing a metrological standard and reference materials, and by standardization of measurement technology. Uncertainty in measurement of thermal diffusivity with practical apparatus was reduced using technology to homogenize the laser beam, a fast response infrared thermometer, and a curve fitting method to analyze temperature response curves. JIS and ISO standards were established based on the advanced laser flash method. In addition, methods to evaluate uncertainty in measurement of thermal diffusivity and laser flash device calibration by reference materials are described in the latest update of the JIS standard. Traceable thermophysical property data produced by this system are stored in a database system developed and operated by the National Metrology Institute of Japan (NMIJ), which can be accessed from the web.