Electromagnetic compatibility, or EMC for short, looks at the unintended generation, propagation and reception of electromagnetic energy in electrical engineering settings. The limitary first became interested in EMC after World War II as a means to mitigate the effects of a lightning strike, high-powered radar beam or nuclear electromagnetic pulse. Military EMC testing can determine which components need more EMC protection and here are some of the ways to apply those protections.
When certain equipment is known to be in danger of electromagnetic pulses, then filtering is an option that can help diffuse the energy and lessen its impact. Filtering means creating radio frequency choke points or line filters at critical junctions such as those between cable entries and switches.
A grounding or shield seeks to divert or reduce energy away from the exposed item. For extra measures, sometimes cables are grounded at both ends or an entire grounded shield may be placed over the item. Grounding has also been used to protect people from being electrocuted.
To further reduce susceptibility, a device may have a kill switch which hardens it against extreme conditions. Fuses, trip switches and circuit breakers are all examples of susceptibility hardening. Military EMC testing can identify the weakest places in an electrical system and mark them for further protection.
In cases when most of the electromagnetic interference comes from nearby machines and electronics, those items may have suppression coils or other implements on them to reduce their output. This is useful when grounding or filtering the vulnerable component would reduce its functionality.
Military EMC testing plays a vital role in the efficiency and reliability of combat electronics. If your company manufactures parts for military use, make sure you also conduct all necessary tests multiple times and at higher voltage requirements than necessary. This kind of redundancy and over-testing may save lives.