<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto"><div>Ludwig,</div><div id="AppleMailSignature">depth transducers in boats can shoot through up to 1/2" of fibreglass when</div><div id="AppleMailSignature">mounted inside the hull. They can't shoot through metal or an air gap.</div><div id="AppleMailSignature"> You could encapsulate the transducer in the required thickness of fibreglass</div><div id="AppleMailSignature">for the depth you are intending. I presume you could use the resin without</div><div id="AppleMailSignature">the glass fibres. I believe their is less shrinkage with epoxy as apposed to</div><div id="AppleMailSignature">polyester resin. Hopefully the shrinkage won't damage the transducer.</div><div id="AppleMailSignature">Make sure there are no air bubbles in the resin or air gap under the transmitting</div><div id="AppleMailSignature">face of the transducer. I would silicone over the wires going in to the resin</div><div id="AppleMailSignature">& over the resin itself where the wires enter; as resin doesn't always seal on</div><div id="AppleMailSignature">the wiring, and the compression of the wire casing can pull away from the resin.</div><div id="AppleMailSignature">You could build a fibreglass enclosure as an alternative to encapsulating.</div><div id="AppleMailSignature">Another alternative would be a metal housing with a fibreglass disk mounted</div><div id="AppleMailSignature">in it like a view port. You would mount the transducer on the disk with epoxy.</div><div id="AppleMailSignature">I haven't tried this myself but through hull mounts are a common practice.</div><div id="AppleMailSignature">Cheers Alan</div><div id="AppleMailSignature"><br></div><div id="AppleMailSignature"><br><br>Sent from my iPad</div><div><br>On 6/03/2017, at 5:16 AM, via Personal_Submersibles <<a href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>> wrote:<br><br></div><blockquote type="cite"><div><font color="black" size="2" face="arial">
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<div>Hello all,</div>
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<div>I'm looking at building a sonar transducer to measure bottom depth for a small ROV project and would like to ask how I should go about pressure-proof/waterproof the system. </div>
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<div>I'm looking at building it with a Arduino Uno Rev 3 microcontroller and a Ultrasonic sensor module.</div>
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<div>-Ludwig Johanning</div>
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