Measurement of the thermal conductivity of composites using heat flow sensors

Abstract A thermal conductivity measuring apparatus that uses heat flow sensors to measure the heat flux through samples was constructed of inexpensive materials. This device was used to measure the thermal conductivity (k) of two composites used in the space program that consist of fibrous or granular components embedded in a resin matrix. The k‐values that were determined ranged from 0.035 to 0.059 Btu/h‐ft²‐°F/ft (−163 to 553°F) and 0.029 to 0.035 Btu/h‐ft²‐°F/ft (77 to 212°F). Thermal conductivity values of the composites conformed to the rule of mixture. The accuracy of the system was found to be comparable to the guarded hotplate and it requires neither a skilled operator nor extensive maintenance.