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From: jbright@schoolnet (Jason Bright)
Subject: Re: Measuring distance by ultrasonic
Message-ID: <Cvx387.13L@cunews.carleton.ca>
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References: <34pmgr$11ei@rs1-hrz.uni-duisburg.de> <34rr8k$m3l@hemp.imel.kyoto-u.ac.jp>
Date: Sat, 10 Sep 1994 14:07:19 GMT
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: Ultrasonic sensors are not too bad, but you must be aware that
: they do not find obstacles all of the time. First of all, they are not
: so good at detecting fabric covered soft material, because, obviously
: these absorb the incoming signal, and not much of an echo is reflected.
: Second, if you use the same transducer for both transmitting and 
: receiving the pulse, then very smooth and hard surfaces can present
: a problem. The high frequency signal is too directive, so if you do not 
: send the pulse at a right angle, it bounces off in a different direction.

: If these problems are OK for you, you can start off with kits available,
: the most popular being the one from Polaroid, a device which
: can give a digital readout, and also easily interfaced with a
: microprocessor.

Any idea where one would get information about these kits?


--
*******************************************************************
Jason Bright
jbright@schoolnet.carleton.ca

"I can't give you a brain, but I can give you a diploma."
	-The Wizard of Oz
