Reverse use of an infrared emissometer for measurement of thermal conductivity

A broadband emissometer based on the ASTM C1371 test method is exploited to measure the thermal conductivity of non-metallic solid materials when these are available in form of thin specimens. The instrument is designed to estimate the infrared emissivity by placing a hot probe with controlled temperature on the specimen surface and measuring the net radiative heat flow rate between probe and surface by means of a thermopile. Placing the probe on a specimen with low conductivity causes the specimen surface to overheat with respect to ambient, and the net radiative heat flow rate between probe and surface to decrease. From the signal measured by the thermopile after the probe-specimen system reaches steady state it is possible to retrieve an estimate of the thermal conductivity