A-weighted or C-weighted?  Only the A-weighted number is valid for
hearing-damage purposes...(C-weighted is flat, A-weighted rolls off the low
end considerably).   Also, was it a $30 Radio Shack meter like mine, or a
"real" one (there are $250 meters available, but to do OSHA industrial
measurements you need the $1200 one as I recall (all prices about 15 years
old...).

I think it would be great to use the RS meter since they're cheap,
available everywhere, and I *think* fairly consistent from meter to
meter.  Also it would be good to have both C- and A- numbers, also possibly
fast and slow meter damping (four readings in all).

david

At 01:05 PM 1/16/2001, Keith Adams wrote:
>I took some noise measurements along the way, using a borrowed sound
>meter.  "quiet" highway driving (i.e. not pushing a big wind, 50 mph or
>so) gave us between 84 and 88 dB.  "noisy" highway driving (i.e. pushing
>a big wind, 70 or 75 mph) gave us 90 to 94 dB.  Both times radio on
>(checked with radio off, but it doesn't do much) fan on #1, sound level
>meter held at about head (sitting) height, between the two front seats.
>Since the onset of hearing damage is 85 dB (i.e. 8 hours a day at 85 dB

David Beierl - Providence, RI
  http://pws.prserv.net/synergy/Vanagon/
'84 Westy "Dutiful Passage"
'85 GL "Poor Relation"