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Re: Ultrasonic

At 16:04 10/8/99 -0500, you wrote:
Ken Fox wrote:

If the object is too close the return and send are overlapping. Also the
sampling rate controls the max distance. Am I right?

You are, indeed, right, Ken. The max. sampling rate for the Pasco device is
120 Hz. That leads to a max. distance of 8 meters, I believe.

poj

Possibly closer to 5 feet.
The two way time available is presumably 1/120 seconds
and if we laughingly take the speed of sound as 1100 feet/second
we seem to have about 10 feet to play with?

Or in translation,
if c is 344 m.s^-1 at 20C and the prf is 120 s^-1 then
the maximal round trip is completed in 344m.s^-1 x 120s^-1 = 2.87 m
a displacement of 1.43 m


brian whatcott <inet@intellisys.net>
Altus OK