Parameter estimations for measurements of thermal transport properties with the hot disk thermal constants analyzer

Abstract

The objective of this work is to improve measurements of transport properties using the hot disk thermal constants analyzer. The principle of this method is based on the transient heating of a plane double spiral sandwiched between two pieces of the investigated material. From the temperature increase of the heat source, it is possible to derive both the thermal conductivity and the thermal diffusivity from one single transient recording, provided the total time of the measurement is chosen within a correct time window defined by the theory and the experimental situation. Based on a theory of sensitivity coefficients, it is demonstrated how the experimental time window should be selected under different experimental situations. In addition to the theoretical work, measurements on two different materials: poly͑methylmethacrylate͒ and Stainless Steel A 310, with thermal conductivity of 0.2 and 14 W/mK, respectively, have been performed and analyzed based on the developed theory.

G-Plus report to Owens Corning-thermal conductivity Measurements of Fiberglass

“…Then a glass plate was put on top of the fibers. The density was 0.048 g/cm 3 . A heavy block was put on top of the glass plate bringing the density to 0.095 g/cm 3 .…”

“…The density was 0.048 g/cm 3 . A heavy block was put on top of the glass plate bringing the density to 0.095 g/cm 3 . The density was calculated using the total weight of the fiberglass, W, and the volume, V. The volume was calculated from the area of the container, A, and the average height of the fiberglass, h.…”

“…The 24 µm fibers were tested first. The total weight of the fibers used was 466 g. The loose packing has a density of 0.032 g/cm 3 . Five thermal conductivity measurements were conducted at room temperature.…”

“…Thermal conductivity is calculated directly from the experimental data. Detailed theory and experimental descriptions of the Hot Disk technique can be found in references [1][2][3].…”

Carbon epoxy composites thermal conductivity at 77 K and 300 K

“…In-plane and transverse thermal conductivity of the composite are measured using a hot probe type method known as the hot disk technique 18,19,20,21 . The sensor is made of nickel foil in the form of a bifilar spiral covered on both sides with an insulating layer of Kapton.…”