Data from: Collaborative Guarded-Hot-Plate Tests between the Laboratoire national de métrologie et d'essais and the National Institute of Standards and Technology

A collaborative study was conducted to determine the long-term measurement performance between guarded-hot-plate facilities at the Laboratoire national de métrologie et d?essais (LNE) in France and the National Institute of Standards and Technology (NIST) in the United States. Thermal conductivity data were compiled from three international comparisons organized from 1997 to 2014. Measurements were conducted in accordance with standardized test methods (ISO 8302 or ASTM C 177) over a temperature range from 280 K to 320 K. Nine different thermal insulating materials (either mineral fiber or expanded polystyrene) were examined covering broad ranges of bulk densities (13 kg?m-3 to 200 kg?m-3) and thicknesses (13 mm to 70 mm). Regression coefficients and their corresponding standard uncertainties for a straight-line model relating thermal conductivity to temperature were computed for material and laboratory. Characteristics of the fits were examined graphically. The results indicate that, over a 17-year interval, the majority of test data from LNE and NIST agreed to within ±1.0 %, or less, for mineral fiber materials and to within ±0.5 %, or less, for expanded polystyrene. The graphical analysis confirmed systematic behavior by material type (that is, mineral fiber versus expanded polystyrene) between laboratories. The results of the study provide useful information to the national metrology institutes about future developments for thermal insulation reference materials and offer potential insights to the measurement science for the guarded-hot-plate method.