Waterproofing Arduino ultrasonic sensor?

[rovdude]

I want to possibly add an ultrasonic sensor to my ROV, connected to my Arduino. I need to know how to waterproof it. I will be putting all electronic stuff in an otterbox dry box... very reliable. I want to use this sensor: http://www.adafruit.com/products/172. Do I need to waterproof the actual sensor part, or can I drill a hole in the drybox with the board in the box, and seal the hole? Will this work? Or does the "ping" part of the sensor also need to be waterproofed? If so anyone know how to do this?

[Kjetil]

It may not help you much but I found this http://www.dfrobot.com/index.php?route= ... uct_id=432 IP67.

[fluxno]

note that sound travels 4.3times faster in water than in air, this will affect the readings.
ref: http://en.wikipedia.org/wiki/Speed_of_sound
how deep are you going?

EDIt: this sensor has been discussed before: viewtopic.php?f=16&t=543 read the thread.

[rovdude]

Well I'm trying to keep the price down... and $100 is too much for one component. Thanks for showing me that though. And I will be reaching 100 feet. In the code for the arduino I should be able to compensate for the different speed of sound in water with some simple math. However the solution posted by seawolf on the other thread was for a sensor with a closed transducer, making it waterproof. Does anyone know where to get one of those??

[fluxno]

However the solution posted by seawolf on the other thread was for a sensor with a closed transducer, making it waterproof. Does anyone know where to get one of those??

there was a link in the thread: http://www.ebay.com/itm/Waterproof-Ultr ... 0721354139

[Seawolf]

If you go with the ebay closed transducers, I suggest buying several. Some of them don't take kindly to waterproofing, for reasons we were never able to figure out. (Although, embedding it in a block of epoxy was probably part of the problem).

Also, there's a good chance you'll need to do some kind of filtering on the data. You end up getting weird echos, or you occasionally don't get a strong enough return to trigger the sensor.


I'm not sure I mentioned this in the other thread, but we also tried the $100 water resistant maxbotics sensors. They really didn't work any more reliably than the ebay ones. That being said, some of the maxbotics sensors have an analog envelope output, which could be really useful if you knew what you were doing. We didn't, so we didn't try it.