VitaTech Engineering was engaged by the Uniformed Services University in Rockville, MD to perform an AC ELF/DC EMI Site Survey, EMI Risk Assessment & Recommended Mitigation Study of two future laboratories adjacent to an M.E.P. Room with transformers, electric panels, conduits, electric pumps and HVAC equipment on the 2nd floor of the medical building. The AC ELF/DC EMI data contained in this report was recorded on 21 August 2007 within the two laboratories by VitaTech.
Survey data revealed that the two future lab areas would be affected by electromagnetic field emissions from two 45 kVA transformers that were located in the adjacent MEP room. Electromagnetic field levels ranged from a 6.38 mG mean and peaked at 36.1 mG on the MEP room common wall. There was also a ground/net current presence emanating from conduits located in the hallway ceiling. In order to achieve the lab specification of 0.3 to 0.1 mG, under average and peak building loads, a decision was made that AC ELF and RF magnetic shielding would be required.
- 3D AC ELF data that shows the electromagnetic field levels in a Future subject chamber to be used to study the lethality effects of blast trauma.
- Profile data shows the three different magnetic field axis and resultant.
- Adjacent M.E.P. Room with transformers, electric panels, conduits, electric pumps and HVAC equipment room where the magnetic field levels peaked at 36 mG.
In the summer of 2008, VitaTech provided and installed a complete turn-key solution that involved the installation of a six-sided 1,400 sq. ft. dual-substrate AC ELF RF magnetic shielding system that included acoustical, low-voltage power lighting, video and HVAC finishing for the Shielded Human Subject Chamber Project for the Uniformed Services University of the Health Sciences in Maryland. The passive shielding technique utilizing conductive and ferromagnetic materials were successful in attenuating the magnetic field levels to less than 0.1mG in the subject chamber.
- A final site survey of the completed shielding system was performed in August 2008 and levels inside subject chamber were less than 0.1 mG after shielding.
- The Subject Chamber for the Blast Lethality and Injury Program was commissioned in the Fall of 2008 and is currently is use.
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