Thermal conductivity measurements at and near room temperature are presented as the basis for certified values of thermal conductivity of SRM 1453, Expanded Polystyrene Board. The measurements have been conducted in accordance with a randomized full factorial experimental design with two variables, bulk density and temperature, using the NIST 1016 mm line-heat-source guarded hot plate apparatus. The thermal conductivity measurements were conducted over a range of bulk density from 37.4 kg/m3 to 45.8 kg/m3 and mean temperature from 281 K to 313 K. Uncertainties of the measure- ments, consistent with current ISO guidelines, have been prepared. Statistical analyses of the physical properties of the SRM are presented and include variations between boards, as well as within boards. Measurements of the foam surface roughness, microstructure, and compressive resistance, are presented. Each unit of SRM 1453 is batch certified for thermal conductivity with the following equation: where λ is the predicted thermal conductivity (W∙m-1∙K-1), ρ is the bulk density (kg∙m-3) and, Tm is the mean temperature (K) valid over the temperature range of 281 K to 313 K. The expanded uncertainty for λ is 1.5 % with a coverage factor of approximately k = 2.
Citation: Special Publication (NIST SP) - 260-175
NIST Pub Series: Special Publication (NIST SP)
Pub Type: NIST Pubs
calibration, bulk density, expanded polystyrene board, fenestration, guarded-hot-plate apparatus, heat-flow-meter apparatus, standard reference material, SRM 1453, thermal conductivity, thermal insulation, uncertainty