[JRTJH]

The "level gauge" shown works on gas pressure at the tank outlet. The pressure is the same with a full tank as with a half full tank and with a tank that's 1/10th full. So, it will read full until it's empty, then read empty as the "last few drops of liquid propane turn to gas and the pressure falls. Incidentally, that's the same time that the furnace flame dies, the stove burner dies and the water heater "sputters and quits"....

I agree with the previous posters, a "gadget that tells you when the tank is empty" but so does the cold stovetop burner..... YMMV

There is another "much more accurate system" that functions on tank weight, but it costs nearly $100 for a dual tank system. So, it's $40 for a gauge set, $100 for a functional gauge set or $40 for an auto-changeover regulator. I think you made the right choice in not only getting a "continuous propane supply" but in not having to go outside at "0-dark-30" to swap propane tanks.....