Thermal interface materials (TIMs) are often used in electronic and microelectronic applications. It can be difficult to determine their characteristics once they are in-situ because it is hard to account for the surface roughness and waviness of the objects the TIM is applied to. This paper explores the application and design of a guarded heat flow meter apparatus that complies with all standards in ASTM D 5470-95 that can accurately ...
This paper introduces a compensation algorithm and a different-layers calibration method that will improve the temperature measurement speed and thermal resistance elimination of a guarded heat flow meter instrument. Without these additions to the method, heat will travel through a thin slice of material too fast for thermal couples to measure accurately. Thermal contact resistance would cause inaccuracy with a thin slice ...
A new analysis method based on the guarded heat flow meter apparatus is proposed to measure the thermal properties of cement-based pastes in a hydrated form. In a steady state, a specimen with 0.4 water-to-cement ratio was found to have a thermal conductivity and a thermal contact resistance of 1.28Wm−1 K−1 and 0.038 m−2 KW−1. A computerized system of heat flow meters provided non-steady ...
Thermoelectric (TE) generators have very important applications, such as emerging automotive waste heat recovery and cooling applications. This study investigates how thermal conductivity, seebeck coefficient, and resistivity of bismuth telluride changes with increasing isothermal aging. The thermal conductivity was tested with the Transient Plane Source (TPS) method. Both bismuth telluride n and p type were tested for 2 wk, 8 wk, 6 mo, 1 yr, and 2 yr of isothermal aging at 240 degrees Celsius. The ...
The thermal conductivity of nanoporous glass alumina films (NGAFs) were theoretically and experimentally studied in this paper. The thermal conductivity of pristine NGAFs and silver nanowire-infused NGAFs of various pore sizes and porosities were measured with a thermal constants analyser based on the transient plane source (TPS) method. Theoretical and experimental results were consistent with one another, and indicated that the pore radius and porosity of the films influenced thermal ...
