Thermal conductivity measurements of four thermal insulation reference materials are presented. The measurements were obtained from an international collaborative test program of guarded-hot-plate laboratories from Canada, France, Japan, United Kingdom, and United States. For each reference material, the collaboration requires five independent replicate measurements taken at a fixed temperature of 297.15 K; and, single-point measurements taken at multiple temperatures from 280 K to 320 K. An important finding from the replicate analysis is the existence of a laboratory-material interaction, that is, there are laboratory-to-laboratory differences in both average value and in variation which change from material to material. The major underlying source for the variability (both within- and between-laboratory) in the replace data is discussed. The analysis of the multi-temperature (280 K to 320 K) data confirms and supports the laboratory-material interaction as found in the fixed-temperature replicate analysis. This multi-temperature analysis further reveals an increasing difference between laboratories as the temperature departs from 297.15 K.
Citation: International Thermal Conductivity Conference
Pub Type: Journals
guarded-hot-plate, international, IRMM, JTCCM, NPL, NIST, NRCC, LNE, reference material, thermal conductivity, thermal insulation