scope:

This part of ISO 10302 specifies methods for measuring the airborne noise emitted by small air-moving
devices such as those used for cooling electronic, electrical and mechanical equipment.
These air-moving devices include such types as propeller fans, tube-axial fans, vane-axial fans, centrifugal
fans, motorized impellers and variations of these types.
This part of ISO 10302 describes the test apparatus and methods for determining the airborne noise emitted
by small air-moving devices as a function of the volume flow rate and the fan static pressure developed by the
air-moving device on the test apparatus. It is intended for use by air-moving device manufacturers, by
manufacturers who use air-moving devices for cooling electronic equipment and similar applications, and by
testing laboratories on behalf of these manufacturers. Results of measurements made in accordance with this
part of ISO 10302 are expected to be used for engineering information and performance verification, and the
methods may be cited in purchase specifications and contracts between buyers and sellers. The ultimate
purpose of the measurements is to provide data to assist the designers of electronic, electrical or mechanical
equipment, which contains one or more air-moving devices.
This part of ISO 10302 is applicable to small air-moving devices used for cooling electronic equipment and for
similar applications where the sound power level of the air-moving device is of interest. Experimental data
show that this method is useful up to the maximum volume flow rate of Equation (1) as a function of nominal
air volume of the plenum used and up to a fan static pressure of 750 Pa.
V
V
Q = Q ×
0
0
max V
V
Q = Q ×
0
0
max (1)
where
Qmax is maximum volume flow rate of the scaled plenum, in cubic metres per second (m3/s),
Q0 is maximum volume flow rate of full size plenum, in cubic metres per second, i.e. Q0 = 1 m3/s,
V0 is nominal air volume of full size plenum defined in Clause 5, in cubic metres, i.e., V0 = 1,296 m3
V is nominal air volume of the scaled plenum, in cubic metres (m3)
NOTE 1 It is noted that the "nominal air volume" means approximate air volume calculated from the outer dimensions
of the plenum. For instance, in case of 1/4 sized plenum, the nominal air volume of the plenum, excluding the leg height,
becomes V = Width 0,3 m × Depth 0,3 m × Height 0,225 m = 0,02025 m3.
For the purposes of this part of ISO 10302, it is recommended to apply the smallest plenum specified in
Clause 5 as possible, provided that the fan's maximum volume flow rate is within the limit of Equation (1).