Rainfall / Drip rate.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.b. Procedure II: This procedure uses (as a guideline) a 276 kPa (40 psig) nozzle pressure that should produce water droplets traveling at approximately 64 km/h (40 mph) when using a nozzle such as specified in paragraph 4.1.2.c. Procedure III: The drip test has a requirement for a volume of water greater than 280 l/m2/hr (7 gal/ft2/hr) dripping through a pre-determined hole pattern. An alternative requirement is for items exposed only to 140 L/m2/hr: Appropriately reduce the drip rate as long as the duration of the test is extended to 30 minutes to ensure the equivalent volume of water falls on the test item.