Gas Flow Calculation

Flowmeters are calibrated for a specific gas (e.g. nitrogen for the RTA). To calculate the flow rate of another gas, multiply the reading by the ratio of the conversion factor or the desired gas to the conversion factor for the calibration gas. For example on the RTA (calibrated for nitrogen), if the indication is 200 ml/min and the gas is Argon, the actual flow rate is 200 * 1.443=288 ml/min.
GAS         FACTOR
Nitrogen    1.00
Oxygen      .996
Argon       1.443
Air         1.00
Helium      1.454
Water Vapor 0.817