Modifying an ultrasonic sensor to work underwater?

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Seawolf
Posts: 33
Joined: Oct 15th, 2011, 10:22 pm

Modifying an ultrasonic sensor to work underwater?

Post by Seawolf »

I've heard rumors that hobby ultrasonic sensors can be modified to work underwater. I was wondering if anyone here had experience with this sort of thing.

Cheers,
-Seawolf
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Mareike
Posts: 51
Joined: Dec 8th, 2011, 1:41 pm
Location: Thailand

Re: Modifying an ultrasonic sensor to work underwater?

Post by Mareike »

http://www.active-robots.com/sensors/ob ... ultrasonic
I will try one of this company. According to some real live ROV techs it will go through 3-6mm PVC if you take as buffer a thin layer of foam to damp the reflection.. But I haven't got it till now..
The company who provides these sensors have a datasheet where is as well a statement of somebody who did it exact this way.
Seawolf
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Joined: Oct 15th, 2011, 10:22 pm

Re: Modifying an ultrasonic sensor to work underwater?

Post by Seawolf »

Thanks, I'll look into it.

-Seawolf
derelicte
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Joined: Aug 1st, 2011, 3:08 pm

Re: Modifying an ultrasonic sensor to work underwater?

Post by derelicte »

I have one of these I can stick in a housing and try. Maybe this weekend.

Image
http://www.maxbotix.com/products/LV.htm
Seawolf
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Joined: Oct 15th, 2011, 10:22 pm

Re: Modifying an ultrasonic sensor to work underwater?

Post by Seawolf »

That would be awesome.
I tried flooding one of those with RTV silicone that has roughly the same density as water. Didn't seem to work.

-Seawolf
derelicte
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Joined: Aug 1st, 2011, 3:08 pm

Re: Modifying an ultrasonic sensor to work underwater?

Post by derelicte »

Mareike wrote:The company who provides these sensors have a datasheet where is as well a statement of somebody who did it exact this way.
got a link for this documentation?
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Mareike
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Location: Thailand

Re: Modifying an ultrasonic sensor to work underwater?

Post by Mareike »

Update, the 'sonar' above I wanted to use as well, but some Lads meant, it is a range finder for air which often also is called 'Sonar' but it has nothing to do with it. They will not work under water and if covered the same result comes out.
But (lucky I have got these real live ROV experts in my friends list) he sent me a suggestion.. How about that one as it is a real Sonar and not a range finder.. Its just the experimental thing to make it proper working..

http://www.conrad.com/SONAR-FISH-FINDER ... ale%2Fm%7D%
Seawolf
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Joined: Oct 15th, 2011, 10:22 pm

Re: Modifying an ultrasonic sensor to work underwater?

Post by Seawolf »

Well I'm going to be using this in a swimming pool, so a real sonar may not work well due to multipath. But I will definitely look into it further. Thanks again.

-Seawolf
derelicte
Posts: 292
Joined: Aug 1st, 2011, 3:08 pm

Re: Modifying an ultrasonic sensor to work underwater?

Post by derelicte »

thanks for saving me the effort.

I guess this would be the US equivalent:

Image
http://www.harborfreight.com/portable-f ... 94511.html

If you find it on sale and use a 20% off coupon, you could probably get it for ~$25.
Dutch-depts
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Joined: Dec 17th, 2011, 5:40 pm
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Re: Modifying an ultrasonic sensor to work underwater?

Post by Dutch-depts »

A sonar works on the principle of sound waves. Sound travels trough air differantly then through water. So even if the sonar is strong enough you'll still need to calibrate it. And sound also travels different through salt- and fresh (sweet) water. So calibrating it in the pool for use in a river/sea wont be perfect.

Those fish finders work a lot better i guess, they are native for the use underwater.

I wouldstill like to know if they work though!
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