Difference in Amounts and Composition of Dew from Different Types of Dew Collectors

Dew was collected using several kinds of collectors at the same time, and the composition was compared. The volumes per unit surface areas of dew formed were different based on the types of collectors. It is found that the amounts of the ions, which in part come from gaseous substances, such as organic acids, nitrous acid, etc., per unit area in dew increase with dew volume per unit surface area. On the other hand, chloride, nitrate, sodium, potassium and magnesium which come from only particles showed no variation with the dew volume per unit surface area. These results suggest that the composition of dew varied by the dew volume per unit surface area formed in the different collectors. Dew is usually collected on a polytetrafluoroethylene (PTFE) sheet. The above result suggests that the dew concentration on the PTFE sheet does not represent the real dew concentration on various materials, such as leaves, cars, roofs, road, etc. To determine the real concentration of dew on a material, the material itself has to be usedas a collector. The PTFE sheet could be used as a standard dew sampler forcomparison of dew formed at various places.