"Cooling Fan Manufacturer" issues in addition to the cooling effect, cooling fan operating noise is also widespread concern. Fan noise is the size of the generated noise of the fan work, influenced by many factors, in decibels (dB). When measuring "Cooling Fan Manufacturer" noise requires less than 17dB noise silencer chamber carried away from the fan a meter, and the fan air intake port is aligned along the direction of the fan shaft, the use of A-weighted manner measurement. "Cooling Fan Manufacturer" spectral characteristics of fan noise is also very important, so we must also use a spectrum analyzer records the fan noise frequency distribution, the general requirements of the fan noise to be as small as possible, but can not exist different tone.