Gas Meter Calculation

1 cubic meter = 1000 liters

One cubic metre is 1000 Litres if it is liquid, but I guess you mean that the gas has vapourised. To get the cubic metres to calculate the amount of heat delivered from the gas measured you have to establish the gas flow at Standard Temperature and Pressure. You must know the pressure in the meter and multiply the reading by a meter correction factor depending on the pressure. It depends how precise you want to be, if the Gas obeys Boyles Law you have to correct for the compression of the gas due to the meter pressure.

A supply pressure of 100 KPa is usually used because the meter correction factor is close enough to 2 as some gases don't quite obey Boyles Law