An Instrumental Gravimetric Method for Indexing Materials, Contaminants, and Corrosion Products According to Their Hygroscopicity

The moisture pickup characteristics of selected dusts, contaminants, corrosion products, and aged insulation and substrate materials have been determined in a dynamic humid environment by instrumental gravimetric analysis. These are compared with pure salts and other standard materials to categorize their relative hygroscopicities during the initial adsorption stage and subsequent stages of moisure pickup. In addition, the minimum relative humidities at which some pure salts and a variety of other substances will pick up moisture are reported.