MIL-STD-810F Method 500.4
Low Pressure/Altitude

Low-pressure (altitude) chamber tests are performed to determine if the hardware can withstand and operate in a low-pressure environment and withstand rapid pressure changes. Examples of some problems that could occur as a result of exposure to reduced pressure include:

1. Rupture or explosion of sealed containers
2. Change in physical and chemical properties of low-density hardware
3. Erratic operation or malfunction of equipment resulting from arcing or corona
4. Overheating of equipment due to reduced heat transfer
5. Failure of hermetic seals

Trimble Yuma®, Nomad®, Recon® and Ranger™ passed the following tests:

• Procedure I, Storage/Air Transport and Procedure II, Operation/ Air Carriage: Tested using 15,000 ft (4,572m) for the cabin altitude (corresponding pressure in a standard atmosphere (57.2kPa or 8.3 psia).
• Procedure III, Rapid Decompression: Tested using 8000 ft (2,438m) for the initial cabin altitude (75.2kPa or 10.9 psia) and 40,000 ft (12,192) for the final cabin altitude after decompression (18.8kPa or 10.9 psia).