ÖNORM EN 12664

This standard specifies principles and testing procedures for determining, by means of the guarded hot plate or heat flow meter methods, the thermal resistance of test specimens either in the dry state or conditioned to equilibrium with moist air, having a thermal resistance of not less than 0,1 m2·K/W and a (hygro)thermal transmissivity or thermal conductivity up to 2,0 W/(m·K). (It is expected that the thermal resistance of most masonry specimen will be less than 0,5 m2·K/W). NOTE 1 The lower limit for measurable thermal resistance is due to the effect of contact thermal resistances, which require special testing techniques described in this standard. Although this standard can be used for testing dry specimens of high and medium thermal resistance, i.e. on products having a thermal resistance of not less than 0,5 m2·K/W, the simpler procedures of EN 12667:2001 are recommended for such specimens. It applies in principle to any mean test temperature, but the equipment design in annex D is essentially intended to operate between a minimum cooling unit temperature of -100 °C and maximum heating unit temperature of +100 °C. NOTE 2 Limits to the mean test temperature are only imposed by the materials used in the apparatus construction and by ancillary equipment. It supplies additional limits for equipment performance and test conditions. It does not supply general equipment design procedures, equipment error analysis, equipment performance check or the assessment of equipment accuracy. It supplies example designs of equipment complying with the requirements set down in this standard. This standard does not supply general guidance and background information (e.g. the heat transfer property to be reported, product-dependent specimen preparations, suggested materials for vapour-tight envelopes when testing moist specimens, procedures requiring multiple measurements, such as those to assess the effec (...abbreviated)