GB/T 21231-2007
Acoustics.Method for the measurement of airborne noise emitted by small air-moving devices (English Version)

Standard No.

GB/T 21231-2007

Language

Chinese, Available in English version

Release Date

2007

Published By

General Administration of Quality Supervision, Inspection and Quarantine of the People‘s Republic of China

Status

Be replaced 2018-10

Replace By

GB/T 21231.1-2018

Latest

GB/T 21231.1-2018

Scope

This standard specifies the measurement method of airborne noise radiated by small ventilation devices. These ventilation units are primarily used for cooling electronic, electrical and mechanical equipment and include propeller fans, axial fans, wing axial fans, centrifugal fans, cross-flow fans, cabinet blowers and variations of these units. This standard describes the method and test equipment for the determination and reporting of airborne noise radiated by small ventilation devices as a function of the flow rate of the ventilation device and the static pressure developed by the ventilation device on the test device. This standard is intended for use by manufacturers of ventilators, manufacturers using ventilators to cool electronic equipment and similar applications, and laboratories performing testing for these manufacturers. Test results obtained using this standard are expected to be used for engineering information and performance qualification, and this method can also be referenced in the purchase specification and the contract between the buyer and the seller. The ultimate purpose of noise emission measurements is to provide data to designers of electronic, electrical or mechanical equipment that incorporates one or more ventilation devices. This standard can be used for the measurement of the total sound power level of small ventilation devices for cooling electronic and similar equipment. The test data show that this method is effective for the occasions where the air flow rate is not greater than 1 m/s and the static pressure of the fan is not greater than 750 Pa. This standard is suitable for type testing and provides methods for manufacturers of ventilation devices, manufacturers of applications such as electronics, and measurement laboratories to obtain comparable results. The method stipulated in this standard refers to GB/T 18313-2001, and provides a method for measuring the sound power level in an environment that meets specific requirements, that is, using the reverberation chamber comparison method based on GB/T 6881.1 or GB/T 14367-2006 Or the direct method of approximate free field above a reflecting surface based on GB/T 3767-1996 or GB/T 6882-1986. The method specified in this standard is applicable to ventilation devices that radiate broadband noise, narrowband noise and noise with discrete frequency components. The method specified in this standard allows the determination of the noise emission level of a single device under test. If the noise emission level of several devices of the same product series is measured, the statistical value of the product series can be determined by the methods specified in GB/T 14573.4 or GB/T 18698. Note: In actual application, vibration, turbulence, insertion loss and other phenomena will change the size of the radiated sound power, so the measurement results obtained according to this standard will be different from the measurement results after the ventilation device is installed on the equipment

GB/T 21231-2007 Referenced Document

• GB/T 1236-2000 Industrial fans-Performance testing using standardized airways
• GB/T 14367-2006 Acoustics. Determination of sound power levels of noise sources. Guidelines for the use of basic standards
• GB/T 18313-2001 Acoustics--Measurement of airborne noise emitted by information technology and telecommunications equipment
• GB/T 3240 Preferred frequencies for the acoustical measurement
• GB/T 3767-1996 Acoustics--Determination of sound power levels of noise sources using sound pressure--Engineering method in an essentially free field over a reflecting plane
• GB/T 6881.1 Acoustics--Determination of sound power levels of noise sources using sound pressure--Precision methods for reverberation rooms
• GB/T 6881.2 Acoustics—Determination of sound power levels and sound energy levels of noise sources using sound pressure—Engineering methods for small movable sources in reverberant fields—Comparison method for a hard-walled test room*， 2017-11-01 Update
• GB/T 6881.3 Acoustics--Determination of sound power levels of noise sources-using sound pressure--Engineering metheds for small,movable sources in reverberant fields--Part 2: Methods for special reverberation test rooms
• GB/T 6882-1986 Acoustics--Determination of sound power levels of noise sources--Precision methods for anechoic and semi-anechoic rooms

GB/T 21231-2007 history

• 2018 GB/T 21231.1-2018 Acoustics—Measurement of airborne noise emitted and structure-borne vibration induced by small air-moving devices—Part 1: Airborne noise measurement
• 2007 GB/T 21231-2007 Acoustics.Method for the measurement of airborne noise emitted by small air-moving devices