There are various gauges, stickers, magnets etc that are available for quick measurements of your gas bottle, but all in the know say these are never accurate or dependable. Unless they are quite expensive and attach to the valve.
So, I did a bit of research, and a practical test of my own and these are the most accurate ways of determining how much gas you have left in the bottle.
Method 1. – By weight
On the gas bottle, normally on the bottom ring, there is a tare weight, which is the weight of the bottle with no gas inside.
Go to your “never friendly” scale in the bathroom and measure the weight of your gas bottle – the weight, less your tare weight (empty bottle) is the amount of gas you have left.
Method 2. – By temperature
Take 2 litres of hot tap water (not boiling water) and pour it down the side of the gas bottle, they say you should see condensation where the gas is, but I did not get that, I waited 15 seconds after pouring the water down the side, and then I used the back of my hand to feel the side of the bottle, sliding it down the bottle until I felt the cold area, that is where the level of the gas is in the bottle.
Method 3. – Movement
I find it best to hold the gas bottle sideways, and sway it side to side, like you are gently bopping to your favourite lullaby, you will feel the gas moving inside the bottle, causing a “wave like effect” inside the bottle, this will tell you there is gas inside the bottle, but obviously not as accurate as those methods above. The more you do this, the better you will be able to guess the amount left in the bottle.
Be very careful with gas, especially in small, confined areas like tents, the fumes are poisonous, especially if there is a slight leak, or if the bottle is not properly off – best practice is to leave the gas bottle outside the tent when inside.
I hope this is helpful.
