Seems I remember a discussion, that Boomer was involved in, that gave me the impression that a Salinity Meter or probe, wouldn't work at all. Let me see if I can find that discussion, or get Boomer to chime in, here.
Salinity is quite easy to read electronically depending on what you want to do with the information. If you want to monitor the value then look into conductivity probes and most of the controllers on the market have one available in some form or another. I use the one connected to the Neptune System Apex and monitor tank and new salt change water. If you are just looking to read salinity while mixing up new water a refractometer is the least costly but if you are into toys I have used the Haana Saltwater Refractometer (which is an electric version of the more manual) and works very well.