Sound Power Measurement

Complied with: Noise Control Ordinance (Chapter 400), Noise Control (Air Compressors) Regulations and Noise Control (Hand Held Percussive Breakers) Regulations


A sound power level is a measure of the total noise radiated by the machine in all directions. Sound power levels are important to equipment manufacturers, buyers, installers, and users for

  • calculating the sound pressure level from a machine, or several machines, at a given distance in a given condition, such as a factory, workshop, office or the home comparing the noise output from different machines,
  • setting specifications for the maximum permitted noise from a machine,
  • comparing machines before and after noise migration works..

In Hong Kong, Air Compressors and Hand Held Percussive Breakers have to specify in machine body and sales manual that equipment are conforming to the EPD Noise Emission Label. The noise emission limit is depended on the air flow capacity for Air Compressor or the mass for Breaker.

Sound power are presented with dB, decibels (dB re 1pW), unit.

click for large image

Air Compressors Sound Power Measurement


Job Reference

1.   The Hong Kong and China Gas Co. Ltd.   (2001)
Application of  Noise Emission Label for Air Compressor