Accurate thermal conductivity testing of insulation materials

Accuracy: Nanoporous Insulation
How does a measurement in a heat flow meter compare to measurements with other standardized techniques such as guarded hot plate (GHP). As part of a Round Robin Test, a nanoporous insulation board was measured with different NETZSCH heat flow meters as well as with a guarded hot plate system (absolute measurement technique). The results obtained by the different instruments are in agreement within 2.5% in the overlapping temperature range. This clearly demonstrates the outstanding performance of the HFM 436 Series instruments.

Accuracy: Ethylene Propylene Rubber Foam
Presented here are the measurement results on an ethylene propylene rubber foam, measured with an HFM 436/3/1 E. Additionally shown are literature values for this material supplied by the customer. It can clearly be seen that the measurement results are in agreement with the corresponding literature data within 2.5%. Furthermore, it can be seen that the HFM 436/3, connected to an external chiller, can perform measurements even at temperatures of -20°C.

Expanded Polystyrene:
One of the most popular materials for the thermal insulation of buildings is expanded polystyrene. The example shows a quality control run on a commercially available expanded polystyrene material (EPS 040). Ten samples of the same batch were tested at 24°C and, according to DIN EN 13163, at 10°C. It can clearly be seen that the deviation between the different samples is less than 1%. The determined thermal conductivity λ 90/90 value according to DIN 13163 was 0.03808 W/(m*K).