For temperate climates: W = 11ARM + DF
For tropical climates: W = 40ARM + DF
BRITISH STANDARDS BS1133-SECTION 19
Formula:
W = Weight in grams of basic desiccant
A = Area in square meters of the moisture vapour barrier
R = Water vapour transmission rate of the barrier in grams per square meter in 24 hours, measuring at 90% of RH and 38 ° C (100 ° F)
M = Maximum time in months of transit and storage
D = Weight in grams of blocking packaging, impact damping and any other hygroscopic packaging materials that are inside the barrier (including cardboard, timber, foam etc.)
F = Factor, depending on the type of stowage
