I did some research on finding an accurate way of determining how much propane is available in each of my 40 lb tanks and came across Mopeka Tank Check
. I bought it and installed it in my RV.
It works fantastic.
It has a magnetic ultrasonic sensor that sticks to the bottom of the tank And sends the data via Bluetooth to your iPad or Android device. It also has it’s own monitor panel that has an LED readout for each tank. I mounted by my master control panel.
The Android and iPad app work great and give you precise readouts of the status of the amount of propane that remains, the battery life of the sensor, and the signal strength from the device. Great, easy to use screens, and it set up in about 5 minutes.
Selecting one of the tanks zooms in for greater detail:
I got it from Amazon