Allow the appliance to run for a suitable timed period.(this does not have to be exactly 2mins but a minimum of 45 seconds is recomended.)
Press Stop.
Record the second meter reading.
Press Calculate.
The calculator uses the difference between the two meter readings.
Imperial Meter - ft³
Leave First Reading and Second Reading blank.
Press Start.
Time exactly 1 cubic foot of gas (1 revolution of the red dial).
Press Stop.
Press Calculate.
The calculator automatically assumes 1 ft³ has been timed and converts this to m³.
Calculation Information
Metric and SMART meters, dont start the stopwatch unitl the number changes and keep the stopwatch running until the number changes (Most Accurate Method) The time is built into this formula so always correct on what time you descide to stop at.