This International Standard specifies equipment and procedures to condition a thermal insulating product to equilibrium moisture content at (23 ± 2) °C and (50 ± 5) % relative humidity. It is also applicable to thermal insulating products with moulded skins but is not normally relevant for faced products or for products with other surface treatments. NOTE 1 The normally specified moisture content is the result of the equilibrium between the atmosphere and the product at (23 ± 2) °C and (50 ± 5) % relative humidity. This International Standard can also be used if a product has to be conditioned to other relative humidities. NOTE 2 The moisture equilibrium may, due to hysteresis effects, differ depending on whether the equilibrium has been reached by absorption or by desorption. In addition, perfect equilibrium can require a very long time to be reached. Therefore, it is necessary to accept equilibrium within a certain accuracy. NOTE 3 For products that do not absorb moisture, conditioning is not needed. It should, nevertheless, be ensured that there is no water on the surface before testing.