I'm guilty of believing the advertising hype & purchased both styles several years ago.
The one like Gina uses is left at home. It's fine for a gas BBQ to remind you to get the spare tank from the garage ahead of time, so you can change tanks before the food gets cold on the grill when the tank does go dry. As Pete observed, it only gives you a warning just before running out, but does allow you to consume all the gas in the tank as long as there is a spare tank.
The
weight scale similar to Frederic's is in our trailer tool box and is used at the beginning of the season to determine how much gas is left in the used tank from last year. It will tell precisely how much gas is inside. During the camping season, when the tank I've been using runs out and been switched to the full one, then the empty one gets filled or exchanged.
No measuring device needed. One 5 gal. (20lb.) tank will generally last months unless you are BBQing 3 (or more) meals a day, running a
propane fueled
generator, keeping the coffee pot hot on the stove while the gas
furnace is running most of the time, the
refrigerator is on gas and six people are dependent on the propane. Even then, I suspect you would probably not run out in less than several weeks.
If your TT is only equipped with a single tank, the
weight scale would allow you to make an informed decision before going camping. I dislike wasting propane so I have my own tanks topped off, versus exchanging a tank which still contains some gas because it
might run out.
Most equipment rental yards will fill tanks.
In our home, with a large cooking range (5 pilots), 3 direct vent furnaces with standing pilots, and 2 tankless hot water heaters (one with a standing pilot and the other with automatic electronic ignition), the
most propane consumed during below freezing temperatures has been 3.3 gallons in 24 hours. When our 300 gallon tank is filled at home, we have our 5 gallon tanks topped off also.
We hope this info helps you make an informed decision.
Wave or say hi if you see us on the road or in a camp ground...
Kurt & Ann K.