Underwater sensor

Expraiser

Hey guys

I'm trying to build a auv using bs2
The problem is that I couldn't find any suitable sensor that works underwater(for navigation, measuring distance)
I'm thinking of wraping ultrasonic range sensor to keep it waterproof.Will this work? Any suggested sensor ?

Any help is greatly appreciated!

Thx

D Faust

If you wrap an ultra sonic sensor it will sense the wrap!!·· I think there might be some special underwater transducers (there is a way to scan the floor of a body of water) but I think that they would be pretty expensive.· Light travels through water so you could probably use some really strong IR light of some sort, but it wouldn't work well for long range.

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--DFaust

Tracy Allen

Take a look at the hydrophone applications for PVDF film at piezo film sensors technical manual

Also Google "pvdf film hydrophone" and you'll get some hits including DIY.

The film has to be relatively thick to match the acoustic impedance of water, and in direct contact.

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Tracy Allen
www.emesystems.com

Expraiser

Not quite get it tho. Is pvdf paper like sheet that can cut and stick wire to it?

Are there any cheap (<$50) sensor that can measure distance underwater?

Thx for the reply

Meepo

I'm working on the same thing myself...what exactly would water damage on the sensor?

Downs

I know it's more than what you wanted to pay but here's one.

http://www.hobbyengineering.com/H2210.html

Phil Pilgrim (PhiPi)

Since marine depth sounders are mass-produced consumer items, you can get them, including a transducer and the electronics, for less than $100. The in-dash meter-housing units with digital readouts are the most compact, and it should be easy enough to hack them to interface with your BASIC Stamp.

Ultrasonic transducers designed to work in air will not work underwater, even when sealed.

-Phil

SRLM

You could just use bumpers... That would cost you all of $1.