Standard practice for manufacturing emergency or entry phones is to provide
them with standard uncoated circuit boards (like the ones in your PC). A few
manufacturers, including Viking, spray the circuit boards with a water resistant
material such as acrylic conformal coating to protect them.
Some emergency or entry phone applications demand extra protection.
Phones that are mounted outside exposed to the elements in salty air near the
ocean, exposed to a corrosive atmosphere or vehicle exhaust all need an
extra measure of weather and corrosion resistance.
- Urethane potting for:
- Maintaining flexibility at low temperatures
- Excellent electrical insulation
- Low stress on sensitive components
- Unaffected by moisture at high temperatures
- Thermal cycling ability
- Hydrolytic stability
- No shrinkage
- Internally sealed push button switch, dip switches and volume control pots
- All wire connections are watertight sealed
- Mylar speaker with weather-proof rubber gasket
- Closed cell foam gasketing to prevent water penetration
- Weatherproof connectors filled with anti-corrosive sealing gel
- Back side of push button switch, LED and microphone are
encapsulated in watertight sealant
- Self-draining microphone boot