– Laboratory scale according to gost 24104, measuring error is less than 0,001 grams. Electrical cabinet dryer (the upper limit of heating is not lower than 110 C, the permissible error of measurement and automatic control of temperature – 2 C) – a set of glass vessels in accordance with gost 25336 (inside diameter or an edge – at least 100 mm or in accordance with the requirements of existing tnla on the test material or product) – laboratory glass thermometer, gost 112, division value 0,1 C – thermograph according to gost 6416 – aspirating psychrometer – caliper, gost 166, the price of division is not more than 0,01 mm – metal ruler according to gost 427, the price of division is not more than 1 mm – a set of templates in accordance with the size and shape of the test samples of aerated concrete – flat glass according to gost 111 – dock (wax, plasticine, a mixture of paraffin and rosin, the sealing construction is sensitive mastic, etc.) for gost 14791 and stb 1087 – reagents, providing the required relative humidity: Mg (NO3) 2 6H2O (magnesium nitrate hexahydrate); CCl2 (anhydrous calcium chloride) according to gost 450; silica gel according to gost 3956; P2O5 (phosphorus oxide (V)); CCI2 (calcium chloride) according to gost 427; Mg (CIO4) 2 (magnesium perchlorate); Na2Cr2O7 2H2O (two-water sodium dichromate); kci (potassium chloride); NH4H2RO4 (ammonium dihydrogen phosphate) and KNO3 (potassium nitrate) in accordance with gost 4517; distilled water according to gost 6709. The means of measurement of concrete to be believed, in accordance with the requirements of stb 8003 or go metrological certification in accordance with the requirements of the stb 8004. Test equipment for concrete shall be certified in accordance with the requirements of the stb 8015. Allowed to use other means of measurement and test equipment, metrological characteristics which make it possible to determine the controlled parameters to the required accuracy. In a laboratory environment or climate chamber in which the tests should be maintained at a temperature (20 2) C, relative humidity (50 3)%, or correspond to the requirements of tnla on the test concrete (product). Water vapor permeability of concrete and products was determined on five samples with square-shaped base with a side (100 1) mm, cut from the middle part of the product to be tested (or in accordance with the requirements of tnla on concrete or a product). The thickness of the test sample should be (30 1) mm..