After being verbally assaulted on another forum, about the indicator gauge for the propane cylinder, by a legend in his own mind that didn't understand it was for a idea of how much was left in the tank for the 85 year old parents. Or don't need to know down to the ounce the amount of liquid in the tank. Or that most people are smart enough to figure out when they need to change the tank, when they are using the indicator gauge.
I went looking for some correct info, instead of his B.S.&hot air! Found this site, has more information than most will want to know. But it is here if you have a need.
Propane 101.com