Holding tank sensors

[PNW Fireguy]

Does anyone know the make and model of the holding tank sensors? I have a 2015 3440RL but am guessing they may all use the same type in a given years span of Montana models. I am looking for a spec or data sheet. Are these resistive measuring type or something different like piezoelectric? I know they have a long history concerning their worth in the forum but my needs are based upon things beyond that. Thanks.

[jcurtis934]

They are basically not much above a bolt sticking into the tank...actually four per tank. The only one that has ever worked on all the rv's we have had is the fresh water tank. Tis why I switched to external tank sensors and electronics in the monitor panel.

[mazboy]

1st rule of thumb in rving. the sensors don't work.


https://www.guaranty.com/blog/rv-tank-sensors/

[PNW Fireguy]

I am painfully aware of the sensors. I am looking at a project and need to see a data sheet and to know if they measure via resistance, inductance, etc. does anyone know the make and mode please?

[jcurtis934]

The "probes" in the tank just use resistance between the four probes sticking into the tank at different levels through any mineral content in the tank to decipher what the liquid level is in that tank. I have never seen any manufacturer part number of the probes as they are installed when the tank is manufactured. One manufacturer of the normal type probes is CP Products. Valera sells the Horst miracle probe, which has a plastic shield to keep crap of all sorts off of the probes. Again, I state, that these probes are nothing more than a glorified bolt stuck through the side of the tank. Hope this additional info helps you out with your project.