1 Scope
This European Standard specifies the equipment and procedure for determining the water
vapour transmission properties in the steady state under specified test conditions
for test specimens of preformed pipe insulation. It is applicable to thermal insulating
products.
It is intended to be used for homogeneous materials (see NOTE) and for products which
may have integral skins or adhered facings of some different material.
NOTE A material is considered to be homogeneous in terms of mass distribution if its density is approximately the same throughout, i.e. if the measured density values are close to its mean density.
The water vapour transmission rate and permeance values are specific to the test specimen (i.e. the product) thickness
tested. For homogeneous products, the water vapour permeability is a property of the material.
If the pipe insulation is cut from a flat product, then the water vapour transmission
properties can be obtained from tests carried out on the flat product with similar
properties in accordance with EN 12086.