[Lorraine Chandler]

I do this when I want to know how much is in the BBQ tank: I use water.

If your pour water on the outside of the tank you will see a horizontal line that forms in the condensation. People say that you have to do it with boiling water, but you don't.

Just as condensation forms on the outside of a glass of ice water (but only where the water is) putting water on the outside of the tank will give you a similar line. That line indicates the top of the liquid propane in the tank (essentially a "fullness" indicator).

For those using 1 pound canisters I weigh mine when they are new on a postage scale. I weigh them again when I am done torching and write the ounces left on the side of the can with a sharpie, then I know how much time I have left.

Both of these tips work for me and they are easy. You could weigh your BBQ tank if you had a nice flat scale with the readout on top like an older doctors scale etc.