On Board LP gauge

I have our SeeLevel tank monitor calibrated so the full (80%) LP tank reads as 100%. Since I only want to know how much liquid is left, that works for me...

Ive filled thousands of tanks and bottles. This is common that the remote does not match the actual float level guage. Trust the float. Now, what about that 1/4- 3/4 thing?
If 80% just a smidge over 75% is full, then shouldnt the guage show 1/3, 2/3, full?
know your tank size. The WC # on it is a weight of LPG if its portable is its capacity of water, so 80% is its capacity in LPG.
On mounted asme tanks, capacity is given in gallons, also in water capacity, so 80% of the gallons capacity in water is the LPG capacity. A common C Mh has 40# tank. about 10 gallons. At 1/4 on the guage, you still have 1/3, or 3,3 gallons.

The sender is a 0-90 ohm rheostat. You should be able to pop it off the tank and take some readings. That will tell you if the sender or gauge is bad.

Richard

Ours inside no longer matches what the tank says either. We just go by the tank.

Sounds like the sender is getting flaky. Mine is broken and someone replaced the gauge with a regular one. I found the electrical sender for $55 on Amazon it just snaps on where the existing one is. Very easy to replace.