Atmospheric Corrosivity Algorithms

There has been some corrosion algorithms developed to compute corrosivity values for given environmental conditions. A couple methods are described here which include the Pacer Lime Program sponsored by the USAF, and ISO Standard 9223. These methods however, use average values to compute their corrosivity indices and only provide a general characterization of atmospheric corrosivity for various environments.

An atmospheric corrosivity severity classification system was developed by Summit and Fink under the Pacer Lime Program to provide management information for the maintenance of aircraft Measurements of environmental conditions were made at numerous USAF bases to compute a corrosivity algorithm. Environmental conditions considered as part of the algorithm are distance to coastal waters, SO2 content, total suspended particles, humidity, and rainfall. A severity index was created and used to schedule the frequency of various preventive maintenance tasks on aircraft. The algorithm developed to schedule the frequency of washing aircraft, is shown in Figure 2.