scope:

This International Standard lays down a test method which defines the use of the guarded hot plate method to measure the steady-state heat transfer through flat slab specimens and the calculation of its heat transfer properties.

This is an absolute or primary method of measurement of heat transfer properties, since only measurements of length, temperature and electrical power are required.

Reports conforming to this standard test method shall never refer to specimens with thermal resistance lower than 0,1 m²⋅K/W provided that thickness limits given in 1.7.4 are not exceeded.

The limit for thermal resistance may be as low as 0,02 m²·K/W but the accuracy stated in 1.5.3 may not be achieved over the full range.

If the specimens satisfy only the requirements outlined In 1.8.1 , the resultant properties shall be described as the thermal conductance and thermal resistance or transfer factor of the specimen.

If the specimens satisfy the requirements of 1.8.2, the resultant property may be described as the mean measurable thermal conductivity of the specimen being evaluated.

If the specimens satisfy the requirements of 1.8.3, the resultant property may be described as the thermal conductivity or transmissivity of the material being evaluated.