PRESSURES

The pressure tests demonstrate if a test item can operate to its standard while undergoing extreme rapid pressure changes. Two of the pressure tests are: altitude (low pressure), and explosive decompression.

ALTITUDE (LOW PRESSURE)
The altitude test determines if an item can operate in a low pressure environment and/or with rapid pressure changes. Low-pressure tests are also performed to determine the ability of seals in components to withstand rupture due to the considerable pressure differentials which may be developed under these conditions. This test is also employed to investigate the influence on components' operating characteristics, including changes in dielectric constants of materials; reduced mechanical loading on vibrating elements, such as crystals and decreased ability of thinner air to transfer heat away from heat-producing components, reduced life of electrical contacts, etc.

Altitude testing is specified in the following:

MIL-STD-202, MIL-STD-798, MIL-STD-810, MIL-STD-1621, MIL-S-3928, MIL-E-5272, MIL-E-5400, MIL-T-5422, MIL-T-7743, MIL-P-7788, MIL-F-7872, MIL-C-7951, MIL-M-7969, MIL-A-8064, MIL-K-8144, MIL-E-8595, MIL-M-8609, MIL-F-8615, MIL-G-10228, MIL-R-11539, MIL-F-13926, MIL-E-16400, MIL-R-21098, MIL-T-21200, MIL-T-28800, MIL-H-83511, MIL-T-0014358, MIL-S-008834, RTCA/DO-160, API-STD-607, UL-471, UL-427, UL-471, ASTM E-644-91, NEMA 250-1997

EXPLOSIVE DECOMPRESSION
This test demonstrates the ability of equipment to withstand rapid changes of external pressure, e.g., the loss of cabin pressure aboard an aircraft.

Explosive decompression testing is specified in the following:

MIL-STD-108, MIL-STD-202, MIL-STD-810, MIL-E-2036, MIL-E-5272, MIL-E-5400, MIL-T-5422, MIL-M-7969, MIL-A-8064, MIL-E-8189, MIL-E-8595, MIL-M-8609, MIL-F-8615, MIL-S-8805, MIL-C-9435, MIL-A-15303, MIL-F-18953, MIL-R-21098, MIL-T-21200, MIL-S-008834, RTCA/DO-160, UL-681, UL-698, UL-886, UL-1203