a. Procedure I: The rainfall rate used in Procedure I may be tailored to the anticipated deployment locale and duration. Although various rainfall intensities have been measured in areas of heavy rainfall, recommend a minimum rate of 1.7 mm/min (4 in/hr) since it is not an uncommon occurrence, and would provide a reasonable degree of confidence in the materiel. MIL-HDBK-310 (paragraph 6.1, reference a) contains further information.