Calculation based on DIN 55474

　　How to calculate the required number of drying agent units:

　　n = 1/a • ( V • b + m • c + A • e • D • t )

　　n = number of the drying agent units

　　a = amount of water vapour to be adsorbed by drying agent unit according to the permitted final moisture content

　　Final Moisture:

　　20% RH a = 3 g

　　40% RH a = 6 g

　　60% RH a = 8 g

　　e = correction factor with regard to the final moisture:

　　for 20% RH e = 0.9

　　for 40% RH e = 0.7

　　for 60% RH e = 0.6

　　v = volume inside the packaging in m³

　　b = humidity content per m³ air subject to the temperature and relative humidity during the packing, i.e. at

　　20°C and 85%RH b = 15g/m³.

　　m = weight of the hygroscopic packing in kg

　　c = factor for moisture content per gram of the hygroscopic packing aid subject to the dry condition for wood, paper and cardboard

　　with an undefined moisture content c = 140

　　with defined pre-desiccation c = 0

　　A = surface of the barrier foil in m²

　　D = water vapour permeability for the expected climate in g/m² D. Regulation in compliance with DIN 53122 or the information supplied by the barrier foil manufacturer.

　　t = transport and storage time in t (days)