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Re: Air Track Ultrasonic



o'scope the transmitter to find it's freq. and then what it's detecting (I assume the transmitting transducer is also the receiver) If it is detecting the whistling, then interpose a narrow pass
filter tuned to the transmit freq. -- you, of course, have tried the system w/o air moving the cart by hand?

bc


Try also contacting Vernier for the circuits and suggestions. I forgotten the name of the engineer I've spoken with there.

Wes Davis wrote:

Tom writes:
A little playing around,
moving the glider by hand, usually yields a solution. I regard any
ultrasonic whistling by the air track as urban myth/legend, even out here
in the sticks.

Tom Ford

Maybe so, but I'm with Dave on this. I have tried everything I can
think of to get usable data of vel. vs. time with CBL and airtrack without
success. The data is so erratic that it is enormously frustrating to the
students.
I have been extremely satisfied with the position/velocity/acceleration data
using the Pasco equipment. They use carts & tracks, tho, rather than air
tracks. I have a substantial investment in air tracks and CBL and, like
Dave,
would really like this stuff to work as advertised.

I note that the experiments in Vernier's lab manual don't use air
tracks.

Wes
At 08:14 AM 8/18/00 -0400, you wrote:
In trying to do a displacement measurement of a sled on an air track
with a CBL using an ultrasonic motion detector, I find that I get some
rather erratic readings that end up giving a very poor velocity vs time
graph.

I am told that the air track produces ultrasonic sounds that confuse the
motion detector. Has anyone found a way around this problem if in fact
this is what is throwing the data off? Any suggestions welcome.

Thanks, Dave Abineri


--
David Abineri dabineri@choice.net