On February 17, 2012 at 10:49, cpchillin said...
Yes you are correct that the pressure varies by temperature but you can go down to Walmart and get a gauge for your gas grills propane tank that gives a reasonably accurate measurement. Analog gauges are on every large propane tank I've ever had. No need to weigh the tank. They just know that it's accurate within a certain percentage and call it acceptable.
I've seen those, but my understanding was they only worked when propane was flowing so it could measue temp. Maybe I'm mistaken.