Around 1984 we were using a too-low 3 semi-anechoic chamber at Wang Labs
to audit out outgoing shipments. Not far away, Glenn Dash was arguing
that this was not nearly accurate enough.
We transported a specimen equipment to Dash, Strauss and Goodhue in
Boxboro, and had his people measure it, then back to our chamber and had
them repeat the test. Then we used correction factors to adjust the
worst case in the chamber to what was seen outside. We never got one
back failing. However, that was just for audit.
I DID find a few things that had been done wrongly by manufacturing,
domestically and in China. Got one memorable call in the middle of
*his* night from a VERY p*ssed off Chinese plant manager. Heh.
Old times. Who audits now?
Cortland Richmond
(ka5s)
On 10/16/2012 1503, John Woodgate wrote:
In message
<of1052898f.98b070cf-on88257a99.006668eb-88257a99.0066f...@hgst.com>,
dated Tue, 16 Oct 2012, [email protected] writes:
Several years ago I was using a 3m FAR for pre-compliance
measurements. They were using a giant BiLog antenna for the
measurements. A constant factor was added to the measured values to
arrive at the OATS value. The reason I stopped using their facility
was because the data didn't correlate well with the 10m
semi-anechoic chamber.
This sort of thing will continue, but we may hope that it doesn't
create an insuperable problem, because the correct technical
procedure would be to establish an empirical correlation (possibly
very complex) between SAR, FAR and OATS by means of a huge
'round-robin' test of hundreds of different product samples in each
environment. Clearly, no-one will pay for this.
The standards-makers have done their best within the realms of the
possible.
-
----------------------------------------------------------------
This message is from the IEEE Product Safety Engineering Society emc-pstc discussion
list. To post a message to the list, send your e-mail to <[email protected]>
All emc-pstc postings are archived and searchable on the web at:
http://www.ieee-pses.org/emc-pstc.html
Attachments are not permitted but the IEEE PSES Online Communities site at
http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used
formats), large files, etc.
Website: http://www.ieee-pses.org/
Instructions: http://listserv.ieee.org/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]>
