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Re: Electromagnetic field question
Mitch J. Belanger wrote:
>
> Radsafers,
>
> An office in our university was recently renovated and the individual work stations rearranged. When the employees in one portion of the office installed and began to use their computers, they noticed that the image on the computer monitor would oscillate. They speculated that electrical wiring which might be present within the wall next to their work stations might be causing this oscillation. To test their theory they positioned the monitors next to the wall and then as far away from it as possible. The oscillations diminished noticeably when the monitors where positioned furthest from the wall. We are working on determining if any electrical wiring exists within the wall and if it does, what kind of power levels it might be carrying.
>
> Do any of you have any experience with a situation similar to this? Any comments and/or assistance on how to remedy these oscillations will be greatly appreciated.
>
> Thank you.
>
> Mitch Belanger
> safmjb@panther.gsu.edu
> ************************************************************************
Mitch and All,
I have had the same situation come up several times. It seems to me that
you can do several things:
1. Relocate the computer monitors away from the wires in the wall.
2. Relocate the wires.
3. Re-arrange the wires so that the + and - wires are closer together
and the 60 Hz magnetic field is more cancelled out.
4. Look for ground leaks from the wires. Sometimes this causes large
magnetic fields. For instance ac current leaking thru metal water pipes.
5. Shield the monitors or the wall with metal which has a high magnetic
permeability, such as soft iron or mumetal alloy (nickel, mostly, I
think).
Wes
--
Wesley R. Van Pelt, Ph.D., CIH, CHP KF2LG
President, Van Pelt Associates, Inc.
Consulting in radiological health and safety.
mailto:VanPeltW@IDT.net
http://shell.idt.net/~vanpeltw/index.html
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