Originally Posted by DocGTO
Debris gets on the sensors and they will be incorrect.... No matter how well you take care of it. LOL
2 things occur with sensors that can result in a bad / false readings and most conversation about what causes it completely disregards one of these. Yes, toilet paper can get 'hung' on a sensor and cause false readings. The bigger culprit causing the bad readings is gunk, dirt, crap, building up on the wall of the tank and providing a conductive path
between the sensors thus causing false readings. By keeping the tank clean, thus the wall clean where the sensors are mounted, this will eliminate false readings. The Horst probes eliminate false readings by building the sensor in a way that prevents a dirty wall between the sensors from conducting. The probe tip of the Horst probe is mounted in Teflon so the electricity has a much harder time conducting thru the dirty wall of the tank and to the next probe.
On several trips I took with the trailer in rain and through some muddy areas I arrived at the campsite and my probe told me the black tank was full. It was fine at home. I discovered dirt and wetness on the outside of my tank in the areas of the probes. (no closed underbelly on mine) Washing that off and getting it dry eliminated the false readings. This convinced me how dirt and buildup in the inside of the tank on the walls would do the same thing. 'Gunk' buildup and slime, is conductive.
So, when you do a heavy cleaning of your tanks and it fixes the false readings it is not the actual probe you cleaned that fixed this, it was the dirty wall the probe is mounted on that got clean.
That's my story and I'm stickin' to it.