Sound Power Measurements
Sound Power Measurements obtained from sound pressure is based on ISO 3744 and 3745 standards. ISO 3744 specifies methods for determining the sound power level or sound energy level of a noise source from sound pressure levels measured on a surface enveloping the noise source (machinery or equipment) in an environment that approximates to an acoustic free field near one or more reflecting planes. The sound power level (or, in the case of noise bursts or transient noise emission, the sound energy level) produced by the noise source, in frequency bands or with frequency A-weighting applied, is calculated using those measurements.
Sound power measurement from sound pressure for anechoic and hemi-anechoic rooms.
Sound power measurement - arrangement of microphones
The methods specified in ISO 3744 are suitable for all types of noise (steady, non-steady, fluctuating, isolated bursts of sound energy, etc.)
ISO 3744 is applicable to all types and sizes of noise source (e.g. stationary or slowly moving plant, installation, machine, component or sub-assembly), provided the conditions for the measurements can be met.
ISO 3745 is used in the determination of sound power levels and sound energy levels of noise sources using sound pressure - precision methods for anechoic rooms and hemi-anechoic rooms.