"Axial Fan" main performance parameters flow, pressure, power, efficiency and speed. Also called air volume flow to flow through the fan per unit of time represents the volume of gas; pressure, also known as pressure, refers to a gas pressure rise in the value of the fan, there is static, dynamic pressure and total pressure points; power is the fan input power, that is, the shaft power. Effective power and fan shaft power ratio known as efficiency. Traffic is the number per unit time fan output fluid. Can be divided into volume flow QV (3 / ms), the mass flow rate Qm (/ kgs), the relationship between volume flow and mass flow rate of Qm = ρQv. Traffic can be installed in the work of the pipeline flow measurement.