"Tiny Cooling Fan" works realized by energy conversion speed refers to the speed of rotation of the fan, usually the number of turns in a minute to measure the rotation, namely: rpm. The number of revolutions of electromechanical winding turns, diameter, blade impeller diameter and base diameter, "Tiny Cooling Fan" leaf shape and the bearings and other factors, the number of revolutions increases, air volume increased accordingly. The size of the transfer value, to a certain extent, represents a size of the wind, when certain conditions, the greater the number of revolutions, noise and vibration will be increased accordingly. Thus, under the "Tiny Cooling Fan" amount of wind to meet the cooling requirements of the case, we should try to use low-speed fan, the fan speed can speed tester.