In our low frequency measurements, we *need* CLEARANCE
distances of over 3 times the distance between EUT and
measurement system to preserve 1% accuracy. Anything
closer deteriorates that accuracy.
I have also seen this clearance ratio in literature
describing how to preserve 1% accuracy in "near field"
measurements.
You don't need 0.1dB, so you can calculate an estimation
for a lesser ratio in accordance with the amount of
degredation you can absorb.
My "guess" is around twice the distance. Anybody have
corroborating numbers associated with the effects they
suffered?
- Robert -
> From: [email protected] [mailto:[email protected]] On
> Behalf Of Elliott
> Mac-FME001
> Sent: Thursday, October 13, 2005 10:02 AM
> To: [email protected]
> Cc: Zakharia Deanna-EDC015; Lewczak John-ETOP37
> Subject: Minimal OATS OFA Question
>
> Hello group
>
>
>
> I have been asked a question about the minimal clearance
> distance for
> constructing a 2-story building near our 30m OATS.
>
>
>
> Using the minimal OFA requirements in ANSI C63.4 / 63.7,
> I am requiring
> a minimal 15m separation from the edge of the ground
> plane behind the
> receive antenna and recommending 100 feet if possible.
>
>
>
> Of course, I would like to have the building constructed
> as far as
> possible away from the OATS....
>
>
>
> Is there anyone out there that has had negative
> experiences with having
> buildings or other objects located at the minimal OFA
> recommendations?
>
>
>
> Any feedback would be appreciated.
>
>
>
> Best regards,
>
>
>
> Mac Elliott
>
-
This message is from the IEEE Product Safety Engineering Society
emc-pstc discussion list. Website: http://www.ieee-pses.org/
To post a message to the list, send your e-mail to [email protected]
Instructions: http://listserv.ieee.org/listserv/request/user-guide.html
List rules: http://www.ieee-pses.org/listrules.html
For help, send mail to the list administrators:
Scott Douglas [email protected]
Mike Cantwell [email protected]
For policy questions, send mail to:
Jim Bacher: [email protected]
David Heald: [email protected]
All emc-pstc postings are archived and searchable on the web at:
http://www.ieeecommunities.org/emc-pstc
