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<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></BODY></HTML>