NNTP-Posting-Date: Fri, 04 Oct 2002 11:24:37 CDT
Subject: Re: Rain intensity to voltage idea... Opinions?
Date: Fri, 04 Oct 2002 16:21:21 -0500
Organization: Majestic 12
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On Fri, 04 Oct 2002 19:23:22 GMT, Jim Thompson
, masquerading as a MSNBC reporter, said
the following to White House press secretary Ari Fleisher during a
press conference concerning the New War:
>(1) Capacitor microphone, amplify noise, rectify and filter output.
Yeah, great for days where the birds are making more racket than the
cicadas and katydids, which is quite impressive to behold out here...
Potentially workable, but I just don't like the idea of non-rain
events causing a jump. I *could* use a high pass filter to eliminate
most living sources, but that won't stop hits from impacts such as
bugs, falling leaves, and bird doo, and near-ulrasonic hits from some
insects and birds, as well as bats depending on the range of the mic.
The worst offender in this type of implementation would be land
vehicles and aircraft, as humans generally don't stop going to and fro
when it rains.
Hey, one very neat thing to try: If you're into monitoring of audio in
nature, purposely build a mic (electret mics excel for this, btw) to
respond to the range between 10Hz and 500Hz, waterproof the device,
and bury it about 2 - 3 feet below the surface in your backyard.
Amplify it greatly, then feed it to a good pair of stereo speakers and
subwoofer in the house. You'll find that you can easily hear
earthworms and other subterrainian critters, passing or idling
vehicles, rainfall, distant explosions or lightning strikes,
reasonably remote falling objects, and even your own footsteps
anywhere within say 50 feet of the mic site with enough amplification.
"Normal" noises such as speech, bird chatter, etc, are very muddled
and faint by comparison. Great fun for all ages :-)
>(2) Bucket with small hole in bottom, then measure height of water in
Then I need electrodes in the water to allow me to graph depth. Every
so often I need to clean the electrodes or recalibrate... Remember, we
are talking rainwater here, not microfiltered, deionized bottled
water. That's what I was attempting to avoid by capacitive coupling.
Not to mention needing to regularly check the hole for debris. Also,
if I make the hole big enough to keep up with heavy downpours, I
eliminate the ablility of tracking very light rains. If I make it
small enough to track very small rains, I eliminate the ability to
accurately track heavy downpours, and make it almost a given that it
will clog up with dead bugs.
I really wasn't after alternatives to my idea, although I do
appreciate the offer. What I want to know is, does my concept just not
work, or is it workable?
Here's an interesting method along the lines of using probes. Use
carbon pencil leads (like drafting compass refills) instead of metal
for a resistance that decreases as the water level rises. Bad points:
The carbon probes will still eventually need cleaning or replacement,
and carbon is quite brittle. Also would probably regularly need to
clean the surfaces where the wires contact the probes. My brother gave
me the idea for this when we were kids. He went though a phase where
he was in love with hydrolysis, and made little pencil carbon arrays
to greatly increase the surface area of gas production without
corrosion on the electrodes. It occured to me that a typical variable
resistor is just a wiper contact along a carbon track, and a long
pencil lead would make a great depth probe.