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Interlaboratory 'Pilot Run' Study of Small Heat-Flow-Meter Apparatus for ASTM C 518



Robert R. Zarr, E S. Lagergren


Thermal conductivity measurements of a high-density glass-fiber thermal insulation material near 24 C are presented for the determination of the precision and bias of ASTM Test Method C 518. The measurements have been conducted by 13 laboratories using small (305 by 305 mm) heat-flow-meter apparatus on three specimens of high-density glass-fiber thermal insulation material that were circulated among the laboratories. Test results are analyzed using ASTM Practice E 691 and subsequently compared to measurements of the same specimens conducted in a guarded-hot-plate apparatus using Test Method C 177. The 95% repeatability and reproducibility indexes for precision have been determined to be no worse than 1.1 % and 4.0 %, respectively. A method for estimating bias is presented.
Journal of Testing and Evaluation
No. 6


bias, building technology, glass fiber, guarded hot plate, heat flow meter, interlaboratory, precision, repeatability, thermal conductivity


Zarr, R. and Lagergren, E. (1999), Interlaboratory 'Pilot Run' Study of Small Heat-Flow-Meter Apparatus for ASTM C 518, Journal of Testing and Evaluation, [online], (Accessed July 21, 2024)


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Created November 1, 1999, Updated February 19, 2017