ISO 12572:2016 pdf free

ISO 12572:2016 pdf free.Hygrothermal performance of building materials and products
The test specimens shall be representative of the product. If the product has natural skins or integral facings, these may be included in the test specimen, but they shall be removed if it is intended to measure the permeability of the core material. If the skins or facings are different on the two sides,specimens shall be tested with vapour flow in the direction of the intended use. If the direction of flow is not known, duplicate specimens shall be prepared and tests carried out for each direction of flow.
Unless the product to be tested is isotropic, the test specimens shall be cut so that the parallel faces are normal to the direction of vapour flow of the product in use.Specimen preparation shall not involve methods which damage the surface in ways which affect the flow of water vapour.
a) Test cups resistant to corrosion from the desiccant or salt solutions they contain; typically cups are made of glass or metal.
The design of cups suitable for testing various different types of materials is described in Annexes A to E.
NOTE Circular cups can be easier to seal and transparent cups allow better control of salt solutions.
b) For certain cups and sealing methods (see Annex A), a template, with shape and size corresponding to that of the test cup, is used when applying the sealant to give a sharply defined, reproducible test area. The template shall have an area of at least 90 % of the specimen to limit nonlinear vapour flow.
c) Measuring instruments capable of determining specimen thickness with accuracy required in 7.2.
d) Analytical balance, capable of weighing the test assembly with the repeatability needed for the required accuracy. Wherever possible, a balance of 0,001 g resolution shall be used. For heavy test assemblies, a balance resolution of 0,01 g may be sufficient (see Annex I for information linking the balance resolution to the duration of test).
NOTE The factors that affect the necessary accuracy of measurement are discussed in Annex I.
e) Constant temperature, constant humidity chamber, capable of being maintained within ±5 % relative humidity around the set point relative humidity and ±1,0 K around the set point temperature. In order to ensure uniform conditions throughout the chamber, the air shall be stirred so as to obtain velocities between 0,02 m/s and 0,3 m/s. If highly permeable materials are being tested, means should be provided to measure the air speed directly over the upper surface of the specimen (see Annex G).
f) Suitable sensors and a logging system to continuously record the temperature, relative humidity and, if necessary, the barometric pressure within the test chamber. The sensors shall be calibrated at regular intervals.ISO 12572 pdf download.