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Acoustics Testing

Sound power

Contact                                                                                                                                                    

Claire Lomax
t: +44 (0)161 295 3030
e: c.lomax1@salford.ac.uk

Sound Power Level Measurement

The amount of noise a machine makes is a key consumer consideration when making purchasing decisions. It is therefore, beneficial for manufacturers to know how ‘noisy’ their products are in comparison to their competitors. In some cases it is even becoming a legal requirement to quote the  Sound  Power  Level  on  energy  labels,  and  on  appliance  and  machine  specifications.

The sound power level is the acoustic energy radiated by a source, which produces a sound pressure level at some distance from the source. While the sound power level is fixed for any source, the sound pressure level will depend on the distance from the source and the acoustic characteristics of the  room  or  environment  it  is  located  in.

At the University of Salford, we have the specialist acoustic facilities to undertake independent measurements of sound power level in laboratory conditions. Some of our sound power tests are UKAS accredited (UKAS accredited Testing Laboratory No. 1262). This information can be used for marketing, and  to  support  the  research  and  development  of  quieter  products.

We have measured the sound power level of sources like:-

  • white goods (dishwashers, washing machines, ovens, fridges, fridge freezers, range hoods)                                                                        
  • vacuum cleaners                                                                        
  • office/IT equipment                                                                        
  • hand-held power tools                                                                        
  • medical equipment (for example oxygen concentrators and injection devices)                                                                        
  • sports equipment (for example motorised golf trolleys)                                                                        
  • shower pumps                                                                        
  • air-conditioning units                                                                        

Sound Power Level Standards

Our independent measurements conform to the major British Standard sound power methods which give general rules for measuring the sound power level that apply to all source type:-

BS EN ISO 3741:2010 Acoustics - Determination of sound power levels of noise sources using sound pressure – Precision methods for reverberation test rooms (ISO 3741: 2010)
BS EN ISO 3743-1: 2010 Acoustics - Determination of sound power levels of noise sources using sound pressure – Engineering methods for small movable sources in reverberant fields - Part 1: Comparison method for a hard-walled test room (ISO 3743-1: 2010)
BS EN ISO 3744:2010 Acoustics - Determination of sound power levels of noise sources using sound pressure – Engineering method in an essentially free field over a reflecting plane.

Details of our current UKAS Scope of Accreditation.UKAS
BSEN ISO 3745:2012 Acoustics – Determination of sound power levels of noise sources using sound pressure – Precision method for anechoic and hemi-anechoic rooms.

Sound Power Level/Airborne Noise: Test Codes                                      

Some sources have test codes that specify mounting conditions specific to that type of appliance/machine. Test codes we have worked to include:-                  

BS EN 60704 1: 2010+A11:2012 Household and similar electrical appliances – Test code for the determination of airborne noise.
BS EN 60704-2-1:2015 Household and similar electrical appliances – Test code for the determination of airborne noise – Part 2-1: Particular requirements for vacuum cleaners


Details of our current UKAS Scope of Accreditation.UKAS-1262
BS EN 60704-2-3:2002 Household and similar electrical appliances – Test code for the determination of airborne noise – Part 2-3: Particular requirements for dishwashers.
BS EN 60704-2-4:2012 Household and similar electrical appliances – Test code for the determination of airborne noise – Part 2-4: Particular requirements for washing machines and spin extractors.
BS EN 60704-2-6:2012 Household and similar electrical appliances – Test code for the determination of airborne noise – Part 2-6: Particular requirements for tumble dryers.
BS EN 60704-2-10:2011 Household and similar electrical appliances – Test code for the determination of airborne noise – Part 2-10: Particular requirements for electric cooking ranges, ovens, grills, microwave ovens and any combination of these.
BS EN 60704-2-13:2011 Household and similar electrical appliances – Test code for the determination of airborne noise – Part 2-13: Particular requirements for range hoods.
BS EN 60704-2-14:2013
+A11:2015
Household and similar electrical appliances – Test code for the determination of airborne noise – Part 2-14: Particular requirements for refrigerators, frozen food storage cabinets and food freezers.
BS EN 60704-3: 2006 Household and similar electrical appliances – Test code for the determination of airborne noise – Part 3: Procedure for determining and verifying declared noise emission values.
BS EN ISO 20361: 2015 Liquid Pumps and pump units – Noise test code – Grades 2 and 3 accuracy.
BS EN ISO 7779: 2010 Acoustics – Measurement of airborne noise emitted by information technology and telecommunications equipment.
BS EN ISO 21649:2006 Needle-free injectors for medical use – Requirements and test methods (ISO 21649:2006).
ECMA-74 13th Edition, June 2015 Measurement of Airborne Noise emitted by Information Technology and Telecommunications Equipment.

Reverberation Chambers

Features of sound power tests at the University of Salford include:-

Fully equipped Laboratory including water supply

Measurements carried out in hemi-anechoic chamber or reverberation chambers

Confidentiality guaranteed

All equipment fully traceable to National Standards

Professional reporting to cover all the requirements of the standard

Technical expertise and independent advice on measurement requirements

Excellent access to main transport routes with convenient loading and storage facilities

Opportunity to witness tests if required