Measure the gas level in a cylinder --- Quick, Practical, and Safe!

To check the level of gas remaining in a gas cylinder there is a trick that does not require a pressure gauge!

Just boil water, and pour it over and around the sides of the gas cylinder. The level of gas will coincide at the point where you feel the cold walls of the cylinder when you touch it with your hands. As a matter of fact, liquefied gas absorbs the heat from the boiling water, which cools down the walls of the cylinder that still contains some liquid gas! 

Please watch the video for a practical demonstration!