Thermtest’s cost effective Heat Flow Meter is the perfect choice for steady-state measurements of thermal resistance and thermal conductivity of insulation products and construction materials. Thermtest’s HFM 100 Heat Flow Meter instrument has been rigorously designed to meet the requirements of international standards including ASTM C518, ISO 8301, and EN 12667.
Operating the HFM is simple – a sample is placed between two heating – cooling plates, and the upper plate, powered by stepper motors positioned in each corner, lowers to contact the top of the sample. Plate contact with the test sample is controlled by a standard pressure applied, or by entering a user defined sample thickness. Sample thickness (L) is measured to the nearest 0.1 mm (0.004 in) by individual optical encoders that control the stepper motors. Integrated logic between stepper motors allows the upper plate to sense and adjust for samples with surface variations, optimizing the contact between plate and test sample during measurements.
A heat flux sensor is integrated into each plate and used to monitor heat flux (Q/A), generated by the difference in temperature (ΔT) between the top and bottom plate at regular intervals, until steady-state heat flux is observed. The composite heat flux is then used to calculate thermal conductivity (λ) and thermal resistance (R) according to Fourier’s Law.