I stand right next to him and watch the scale.The scale is in a little dark shed, I should memorize the tank tare and see where it is set.
Edit - I have a respect for gas and gas over liquid tanks under pressure. I worked in a setting where even though I did not use much of what was in our lab, we had to watch the safety training films. Safety rules are there for a reason. Stuff happens, the results can be bad news. It doesn't happen all the time, but the results can be very bad.
So how many of you have been through the safety training and videos and still store your tanks inside?
I will shut up now.
Son of a firefighter here. Seen pretty much all of it on safety. I am willing to bet that more houses burn down from Christmas trees each year than propane leak fires (of course most propane fires are caused by ignition from the operating device, rather than the tank leaking when disconnected). I agree that we should be safe, just that storage of a propane tank and lawnmower gas, chainsaw gas and weed whacker gas in my gararage away from combustion sources is a reasonably safe practice IMHO. And as always, reasonable minds may differ and I am okay with that.