MIL -STD-810 is a United States Military Standard governing Environmental Engineering Considerations and Laboratory Tests making specifications for environmental designs and test limits for an equipment, as approved by all wings of the US Department of Defense, the norms being adopted for military applications and commercial purposes as well.
The uniqueness is that MIL-STD-810 will subject an equipment to the conditions that it will work through all its life under chamber test methods rather than imitating the environments.
It is a tri-service partnership consisting of the USAF, the USArmy and the USNavy, and functioning as a technical nodal point.
The methods evaluate equipment’s functioning under environmental stresses, its environmental life cycle, deficiencies if any, confirm conformities with contractual obligations, and define environmental stress sequences and durations.
MIL-STD-810 stipulates testing in environmentally- varying real-world conditions such as low pressure for different altitudes, high and low temperatures, rains-wind-blown and freezing types, salt fog for rust testing, fungus and humidity, dust and sand surroundings, turbulent atmosphere, gunfire vibration, ordinary shocks and transport shocks, acceleration, leakage and random vibration.
Origin and development of MIL-STD-810:
The Army Air Force made out the first specification in 1945 enunciating a formal methodology for equipment testing under simulated environmental conditions. Since then, the specification has undergone a number of revisions nick-named MIL-STD-810 [6,7,8] and MIL-STD-810 [D,F,G] stipulating various conditions. The biggest advantage was that the design engineer, using such documents, gained a clear appreciation of interpretation, application and connection of environmental testing. And 1965 saw the USAF releasing a technical report on natural and induced environmental tests for air and ground equipment.
a) In between, The Institute of Environmental Sciences and Technologies, a technical society released History and Rationale of MIL-STD-810 bringing out the actual aim and wisdom behind such testing methods, change of procedures and guidance; it further threw light on future direction and plans also.
b) Then, a release made in 1962 mentioned in a single sentence enabling modification of tests to reflect environmental positions, which was further followed up with more elaborate details for shock and vibration tests under real-world conditions called Mil-STD -810 [D]. And, revision MIL-STD-810 F further added more test schedules creating test chamber for likely encounters in the product’s life time.
c) MIL-STD-810 G incorporated Test Method 527 involving multi-axis, simultaneously exciting test axle resonances and real-time vibrations.
Laboratory findings have limitations. In reality, real-world conditions in many cases could not be fully replicated in laboratories. So, what is achieved in a lab work, might not always be achievable in real-world scenarios. Hence, proper technical judgment to extend laboratory findings to the real working conditions is to be made.
Met Laboratories, Trialon Corporation and Cascade Technical Sciences Inc. are some laboratories engaged in testing of equipment for the Military in this regard.
Some books used as reference to fix standards are as follows. Environmental Conditions for Airborne Equipment, Environmental Test Methods for Defense Material, NATO Environmental Guidelines for Defense Equipment, and Shock Testing Requirements for Naval Ships.
MIL-STD-810 is a benchmark for gauging the performance of an equipment under most stressful conditions related to real-world requirements. As of today, it has undergone a number of revisions, which means it has accommodated latest tests compelled by change of circumstances of the day. That is resilience towards “excellence” which makes basically the standard, a robust foundation for all changes.