Explanation to standard condition for gas flow measurement:
About gas volume flow measurement, standard condition is the temperature & pressure condition which is publicly recognized for trade settlement. For example, United states and latin America take 15℃, 101.325 Kpa as standard condition. China take 20℃, 101.325 Kpa as standard condition, other countries take 0℃, 101.325 Kpa as standard condition.
Gas volume changes accompany with temperature and pressure, it is the knowledge of the ideal gas state equation. In the actual application, For gas fluid, there are standard condition and process condition.
If the flow unit is Nm3/h, it indicates the flow rate is at standard condition.
If the flow unit is Am3/h, it indicates the flow rate is at process condition.
When writing flow unit, many customers are accustomed to omit the alphabet “N” or “A” in front of “m3”, it is less rigorous, so need to confirm the flow unit m3/h is at standard condition or process condition.
Generally, the catalog of gas flow meter such as Vortex flow meter, Thermal mass flow meter and gas turbine flow meter only present measure range of the flow rate under process condition.