Gas stop valve

[Dennis66]

I was thinking of ordering a gas stop for the propane, can you tell me how accurate the gauge is?

[openrangeowners]

The gauge on ANY propane gas stop-type valve is only sensing pressure. The pressure is dependent on temperature, so it will be somewhat like an indicator (either you have propane or you don't. The actual quantity of propane in the bottle cannot be easily determined by pressure. There are propane level detectors that use either weight (ie: a scale) or ultrasonic (ie: measure the height of the liquid inside the metal container) or temperature (putting it on the outside of the container so it will tell you the temperature difference from bottom to top - essentially a strip that changes color with different temperatures).

Weight is the most accurate. The ultrasonic sensors are pretty cool and fairly accurate. The temperature strips seem to work if the outside temperature is not at an extreme. The gauges like you mention are at most a guesstimate or they will absolutely indicate when you are empty. Not much different than the green/red indicator you already have.