ASA S12.11 Part 1 – American National Standard for Acoustics – Measurement of airborne noise emitted and structure-borne vibration induced by small air-moving devices – Part 1: Airborne noise measurement (a nationally adopted international standard).

This part of this American National Standard specifies methods for measuring the airborne noise emittedby small air?moving devices (AMDs), such as those used for cooling electronic, electrical, and mechanicalequipment where the sound power level of the AMD is of interest.

Examples of these AMDs include propeller fans, tube?axial fans, vane?axial fans, centrifugal fans,motorized impellers, and their variations.

This part of this American National Standard describes the test apparatus and methods for determiningthe airborne noise emitted by small AMDs as a function of the volume flow rate and the fan static pressuredeveloped by the AMD on the test apparatus. It is intended for use by AMD manufacturers, bymanufacturers who use AMDs for cooling electronic equipment and similar applications, and by testinglaboratories. It provides a method for AMD manufacturers, equipment manufacturers and testinglaboratories to obtain comparable results. Results of measurements made in accordance with this part ofthis American National Standard are expected to be used for engineering information and performanceverification, and the methods can be cited in purchase specifications and contracts between buyers andsellers. 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 AMDs.

Based on experimental data, a method is given for calculating the maximum volume flow rate of the scaledplenum up to which this part of this American National Standard is applicable.