All my sending units are WEMA. I had to replace 2 in the water tanks and they faild too... reed switches are bad in the unit. This is reason I am looking into matter what would be the best solution. I have polypropylen tanks they are translusent, but for convenience I prefer some level gauges.
Hart unit are unresonable expensive... I looked at the parts needed to ass'y unit and cost is less then $150...
I am making my own!!!
The tank tender has been around a while and most I see are inoperable. They work best on water tanks and the dip tubes tend to plug with effluent on holding tanks.
Airmar has some new tank transducers out which should prove to be great units. These units are made by
Offshore Systems in the UK and distributed in the US by Airmar. They are a no moving part product, no cleaning etc. and are NEMA 2000 tank sensors for fresh or black water. They run about $180 - 230 each.... Just install the senders and plug into the NEMA network and most plotters can display the tank levels. No
proprietary display should be necessary if you have a compatible N2K plotter/system.
Xintex also has some pneumatic tank sensors but I have had to repair/replace a lot of the older style LMM-1's and they made the new ones non-backward compatible, a real PITA to say the least. Lots of Tiar's came from the factory with these and I have fixed my fair share.........