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Publication Citation: Uncertainty Analysis of Thermal Transmission Properties Determined by ASTM C 177

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Author(s): Robert R. Zarr;
Title: Uncertainty Analysis of Thermal Transmission Properties Determined by ASTM C 177
Published: March 01, 2010
Abstract: An uncertainty analysis for steady-state thermal transmission properties determined by the National Institute of Standards and Technology (NIST) 1016 mm Guarded-Hot-Plate apparatus is presented for fibrous-glass blanket and expanded polystyrene board. The uncertainties are presented for the guarded-hot-plate apparatus in the single-sided mode of operation covering specimen heat flows from 0.5 W to 5 W. The relative expanded uncertainties for thermal resistance increase from 1 % to 3.5 % for thicknesses of 25.4 mm to 254 mm, respectively. Although these uncertainties have been developed for two thermal insulation materials, the results are indicative of other insulation materials measured at a mean temperature near 297 K (23.9 °C). This assessment of uncertainties is of particular interest for users of Test Method C 177 that operate similar apparatus at low heat flows (i.e., near or less than 1 W). Implications for laboratories that develop secondary standards from NIST calibrations are discussed.
Citation: Journal of Testing and Evaluation
Keywords: building technology; calibration; expanded polystyrene board; fibrous glass blanket; guarded hot plate; heat flow; thermal conductivity; thermal insulation; thermal resistance; standard uncertainty; expanded uncertainty
Research Areas: High Performance Buildings, Building and Fire Research, Sustainability Metrics and Tools
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