While i have never rugged AN arduino, I wont to add a measurement company and have ruggedized tailored integrated kit to be used in unsafe + terribly rough conditions, and these
few tips from past experience came to mind.
Potting: once your board is tested, place it in a very little fittingly sized receptacle and fill with potting epoxy.
for bench prototyping, at a pinch you can use candle wax (but NOT for field, heat can cause wax to vaporize and become fire risk).
pro tip: bear in mind that the consistency of your potting compound changes with native close temperature, so always test one board before doing a batch or you may wreck a
lot of kit (epoxy can either not fill into all areas, or will be too thin and seep into connectors)
Cable bleed: each side of cable shielding should be properly sealed.
liquids feed through cable shielding and might cause huge issues.
Enclosure: If heat is a problem typically employing a metal finned enclosure for the device can wick away enough heat.
If power usage isn't any issue, you can use a TEC to assist.
When waterproofing, always use the right kind of sealant, some sealants release vapor that will corrode copper over time.
Also, use marine-grade screws in field if you do not wish to own to use a drill to re-open it later.
Connectors: we have a tendency to had heaps of joy with the Bulgin Buccaneer vary.
They aren't good in high apace dynamical temperature setting tho', we have a tendency to had to pot them when installation for best results.