a. Procedure I – Rain and Blowing Rain: 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. During the pretest set-up, rain fall measurements
should be taken at a minimum of 5 random locations. The average of these rain rate measurements should
be within 10% or +/- 0.1 mm/min (0.25 in/hr) of the specified value, whichever is less. To ensure a uniform
distribution of simulated rain on the test item each measurement should be within 25% or +/- 0.2 mm/min
(0.5 in/hr) of the specified rain rate whichever is less.
b. Procedure II – Exaggerated: This procedure uses (as a guideline) a 276 kPa (40 psig) nozzle pressure with a
flow rate of 20.8 L/min (5.5 gal/min) 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 – Drip: 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 (3.5 gal/ ft2/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
Açıklama
Özellikler
Genel
Working Dimensions | 40′ x 40′ x 40′ (Inches) / 100cm x 100cm x 100cm, 60′ x 60′ x 60′ (Inches) / 150cm x 150cm x 150cm |
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Test Procedure | a. Procedure I – Rain and Blowing Rain, b. Procedure II – Exaggerated, c. Procedure III – Drip, Combinated |