This standard specifies principles and testing procedures for determining, by means of theguarded hot plate or heat flow meter methods, the thermal resistance of test specimens having athermal resistance of not less than 0,5 m2·K/WNOTE 1 The above limit is due to the effect of contact thermal resistances. An upperlimit for measurable thermal resistance depends upon a number of factors described in thisstandard, but a unique figure cannot be assigned.It applies in principle to any mean test temperature, but the equipment design in annex D isessentially intended to operate between a minimum cooling unit temperature of -100 °C andmaximum heating unit temperature of +100 °C.NOTE 2 Limits to the mean test temperature are only imposed by the materials used inthe 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, equipmentperformance check or the assessment of equipment accuracy.It supplies example designs of equipment complying with the requirements set down in thisstandard.This standard does not supply general guidance and background information (e.g. the heat transferproperty to be reported, product-dependent specimen preparations, procedures requiring multiplemeasurements, such as those to assess the effect of specimen non-homogeneities, those to testspecimens whose thickness exceeds the apparatus capabilities, and those to assess the relevanceof the thickness effect). Due to these limitations, this standard should be used in conjunction withthe product standard relevant to the product to be tested.Although intended primarily for building materials, it can also be used for specimens of anymaterial that conforms to the requirements specified.