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<DIV><SPAN class=086254215-16022005><FONT face=Arial color=#0000ff size=2>So
true, Earl ...</FONT></SPAN></DIV>
<DIV><SPAN class=086254215-16022005><FONT face=Arial color=#0000ff size=2>One
time, when a local club had to compile this data for local
authorities, the property-line noise readings were inconclusive, and showed that
the ambient noise at the complainer's property line was above the standard, even
if we didn't fly. For that, a calculation of the expected noise at some large
distance (-6 dB for every doubling of distance above the 3meters) was the only
way to show that we were an insignificant part of this guy's ambient. 96 dB @ 3M
gives 65 dB @ 352 feet. I have seen 55 dB ordinances at the property line.
That's close to 1400 feet away from the model.</FONT></SPAN></DIV>
<DIV><SPAN class=086254215-16022005><FONT face=Arial color=#0000ff
size=2>Regards,</FONT></SPAN></DIV>
<DIV> </DIV>
<P><FONT face="Times New Roman">Dean Pappas</FONT> <BR><FONT
face="Times New Roman">Sr. Design Engineer</FONT> <BR><FONT
face="Times New Roman">Kodeos Communications</FONT> <BR><FONT
face="Times New Roman">111 Corporate Blvd.</FONT> <BR><FONT
face="Times New Roman">South Plainfield, N.J. 07080</FONT> <BR><FONT
face="Times New Roman">(908) 222-7817 phone</FONT> <BR><FONT
face="Times New Roman">(908) 222-2392 fax</FONT> <BR><FONT
face="Times New Roman">d.pappas@kodeos.com</FONT> </P>
<BLOCKQUOTE dir=ltr style="MARGIN-RIGHT: 0px">
<DIV class=OutlookMessageHeader dir=ltr align=left><FONT face=Tahoma
size=2>-----Original Message-----<BR><B>From:</B> discussion-request@nsrca.org
[mailto:discussion-request@nsrca.org]<B>On Behalf Of </B>Earl
Haury<BR><B>Sent:</B> Wednesday, February 16, 2005 10:29 AM<BR><B>To:</B>
discussion@nsrca.org<BR><B>Subject:</B> Re: Sound Level meter
requirements<BR><BR></FONT></DIV>
<DIV><FONT face=Arial size=2>Bob</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Lance is correct in that for noise data to be
useful in a legal environment one would want to cover all the bases regarding
instrument accuracy, certification, and operator qualifications. The RS
meter is a poor choice in this situation, RS specifically mentions in their
literature that the meter is not ANSI compliant. The RS meter is OK for
comparisons - but it will drift quite a bit with temp changes.
</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Most sound level limits imposed by ordinance deal
with the noise level at the property line, usually on the order of 65 dB-A
(daytime/ residential) or 68 (non-residential) max in the areas most flying
facilities are located. For legal use, a club would probably be better served
by a record of the sound level at the property line over the time model
activity is ongoing and not. (Recording meters are readily available.) Often
such data demonstrates that the modeling contribution is a small
increase over normal background noise. A search of litigation regarding
modeling noise reveals that the model facility usually prevails when the
property line limits are met.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>A good source of info, including local ordinances
is available at: <A
href="http://www.lhh.org/noise/">http://www.lhh.org/noise/</A></FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Earl</FONT></DIV>
<DIV> </DIV>
<DIV>----- Original Message ----- </DIV>
<BLOCKQUOTE dir=ltr
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=bob@toprudder.com href="mailto:bob@toprudder.com">Bob Richards</A>
</DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=discussion@nsrca.org
href="mailto:discussion@nsrca.org">discussion@nsrca.org</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Wednesday, February 16, 2005 7:45
AM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: Sound Level meter
requirements</DIV>
<DIV><BR></DIV>
<DIV>Good point.</DIV>
<DIV> </DIV>
<DIV>For my use (making comparisons) the RS meter is fine. The club I
formerly belonged to also used them for enforcing a club-imposed noise
limit.</DIV>
<DIV> </DIV>
<DIV>However, if it comes down to enforcing a local noise ordinance, a
calibrated meter traceable to NIST would probably be required. I'm not sure,
but I don't see why you would not be able to have a RS meter calibrated,
although I am sure the measurement uncertainty would not be very good. I'm
sure the calibration would probably cost more than the RS meter.</DIV>
<DIV> </DIV>
<DIV>What are/were the circumstances of "needed in a court of law" are you
referring to?</DIV>
<DIV> </DIV>
<DIV>Bob R.<BR><BR><B><I>Lance Van Nostrand
<patterndude@comcast.net></I></B> wrote:</DIV>
<BLOCKQUOTE class=replbq
style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #1010ff 2px solid">Earl/John,<BR>Our
club bought a RS meter and I remember Gray taking it to a contest where
<BR>either Earl or Mike Harrison had their Extech. The RS meter was 2 db
off <BR>and had no calibration. We then bought the Extech and found that
the <BR>calibration ability and the specs are needed in a court of
law.<BR>--Lance<BR><BR></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE></BODY></HTML>