How to protect an arduino from dust and moisture ? I have already made an RPM datalogger using arduino and placed it in industry.I wanted to protect arduino from dust and moisture.I also want to know the life of arduino.
For a reasonably robust housing with fairly low effort, you could try using a Fernco PQC-104 4″ Qwik Cap rubber boot on a 4" PVC drain cap. Both are available for a few dollars from most hardware stores. Then use cable ties to affix your electronics to a knockout cap placed inside.
You can see a few photos of loggers built into these housings at: http://edwardmallon.wordpress.com/2015/10/24/diy-arduino-logger-build-instructions-part-3/