Calibration of Wastewater Tank Monitor
Executive summary for non-nerds:
The tank monitor panel for the wastewater aft tank shows quarter full, even when the tank is empty. This is irritating and falsely makes you think there might be a clog. The root cause is that it’s impossible to follow the installation rules when applying the sensor aluminum foil. There is a big metal object in the way, and you cannot separate the foils enough to get the stated separation for a zero reading when empty.
The resolution is to separate the foils, where possible, add diodes to subtract the electrical zero bias.
This makes the monitor show empty when truly empty, and full when full, and everyone is happy...
If you want the full story, read below...