Adjust the speed of the fan to the desired speed using the tachometer to measure precision.Adjust orifice plate, all trials up to change the orifice plate must use every new round speedometer tachometer for precision.
Adjust the speed of the fan to the round speed need to use tachometer measured for accuracy fine orifice plate were all value. When changing the orifice plate will need to use tachometer speed around every time to accuracy