A way to tell if your gas cylinder is close to empty

For those not living in India, a little background information. In India, cooking gas (LPG) is delivered in metal cylinders and a regulator and rubber pipe are used to connect the cylinder to the stove. We do not have a centralised gas system like some countries do. (The safety of this kind of arrangement is another issue and I won’t go into it here.)

The domestic gas cylinders, which are usually red in colour, are pretty robust and serve their purpose. Except in one situation. There is no direct way to figure out how much gas is left and when you need a refill. The way you find out is when your stove doesn’t light up because you have run out of gas.

This is a problem because depending on your gas distributing agency (and the supply of gas), your new cylinder could take anywhere from 2 to 10 days, sometimes more if the supply is really hit. Let’s say it’s an average of 3 to 4 days. If you knew before your cylinder ran out and booked in advance that would save you a whole lot of trouble.

You can weigh the cylinder and estimate how close you are to empty but that could result in your wasting gas and it isn’t an optimal solution anyway. I know that some people have two gas connections so that in case one runs out they have a backup but that’s not feasible for people who’re on the lower rung of the income scale. Sometimes companies don’t allow for two gas connections. That’s besides the point.

I cannot believe that nobody has come up with an innovative design to enable customers (like me) to figure out how much gas is left in a cylinder. I don’t even need to know an exact number, even a indicator that displays when you need to call for a refill would do. I remember reading sometime about cylinders that have a sensor along the length of the cylinder that changes color to indicate the level but I’ve not seen such cylinders in action.

The solution would have to be something that doesn’t require the cylinders to be redesigned and would have to be reasonably inexpensive. I imagine that some sort of pressure gauge would work, maybe before or after the regulator. I’ve not done any testing or designing, so this is speculation.

Anyone have a different experience with gas cylinders in India or any other country?