So, I’ve sealed up my hydrophone. I used Olive Oil to fill the case. I’m slightly worried about it becoming rancid over time, but I didn’t have any mineral oil at my disposal, and didn’t fancy sucking some out of my car.
Around the wire I used a heavy duty glue (Meant for sealing walking boots.. so I figured it’d do just fine for sealing the hydrophone) and silicone sealant to seal the inside of the cap, just to be extra sure. The cap is also glued onto the case to prevent it from coming off during operation. I need to make friends with someone who has access to a laser cutter, or a 3D printer to try and make some sort of case to further strengthen the camera case and prevent the lid from coming off during operation.
The image above shows what happens if you put the hydrophone on top of the computer case. In air the output from the hydrophone is almost nothing, just a bit when you touch the case. Hopefully this will mean that the hydrophone works well when in contact with water… We shall see! I’ll field test it shortly.