Gated Ultrasonic Transmitter

If you going to measure distance, you should two devices.

Like this:

No, I am not measuring distance. Just making a transmitter.

David White

On Sun, 25 Mar 2012 09:25:38 -0600 in sci.electronics.design, hamilton wrote,

Polaroid didn't.

And do you know why ??

I have a Sonin Multi-Measure that also (normally) works with just one device. It bounces sound off of the wall or other structure to which you want to measure the distance. Works quite well.

If there is no reflective surface at the other end such as if you want to measure foundation digging dimensions before anything is built or when the distance is very large then you'd need a 2nd echo device.

I'd use a tape measure ;-) ...Jim Thompson

Behind the building at one of my clients you would most definitely prefer the ultrasound method. There's some gators out there.

What is the acoustic _absolute_accuracy_ at 100' ? A foot? ...Jim Thompson

The manual says 3-3/4 inches at 60ft.

At what temperature range? If you want your footer built with that kind of accuracy, go ahead. We'll measure the south line today, but wait until tomorrow to do the north line because there's a cold front coming thru and it's going to rain :-) ...Jim Thompson

Note that there are laser-based range finders in the same price ballpark that appear to be rather more accurate. E.g.,

-- 1/16" at 130', $90.

You can't measure the actual casing for the foundation with that. But for trenching it's usually ok.

When I laid carpet tiles a couple months ago I did it for kicks. Measured the first tile marker line with the Sonin, switched to metric because I use a German "Zollstock" with centimeters to cut tile. Said

Yep. ...Jim Thompson

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