Radio Frequency Interference Evaluation of a Single Skin S-280B Shelter.
HARRY DIAMOND LABS ADELPHI MD
Pagination or Media Count:
An S-280B shelter was subjected to MIL-STD-285 radio frequency interference RFI tests in the normal configuration and with the curb-side and rear exterior skins removed. Although the shelter had been damaged before testing, it was repaired to bring its performance up to meet the MIL-STD-285 requirements of a new shelter. The measurements after the skin was removed showed a 20-dB reduction of shielding for electric E- field at the higher frequencies and a 14-dB reduction of shielding for magnetic H- field at the lower frequencies. Sealing a gap between the interior wall and the door frame restored one-third of the low-frequency H-field shielding and about 10 dB of the high-frequency E-field shielding. The conclusion is that the leakage is dominated by the seams. An 80-dB single skin shelter must have either welded seams all the way around or equivalent or else multiple walls each having RFI shielding. Author
- Electricity and Magnetism
- Electromagnetic Pulses