The method specified in ISO 3747:2010 is suitable for all types of noise (steady, non-steady, fluctuating, isolated bursts of sound energy, etc.) defined in ISO 12001. The method is primarily applicable to sources which emit broad-band noise. It can, however, also be used for sources which emit narrow-band noise or discrete tones, although there is a possiblity that the measurement reproducibility is then degraded.
The noise source under test can be a device, machine, component or sub-assembly, especially one which is non-movable.
The test environment that is applicable for measurements made in accordance with ISO 3747:2010 is a room where the sound pressure level at the microphone positions depends mainly on reflections from the room surfaces. In measurements of ISO 12001:1996, accuracy grade 2 (engineering grade), background noise in the test environment is low compared to that of the noise source or reference sound source.
Information is given on the uncertainty of the sound power levels and sound energy levels determined in accordance with ISO 3747:2010, for measurements made in octave bands and for A-weighted frequency calculations performed on them. The reproducibility conforms with that of either ISO 12001:1996, accuracy grade 2 (engineering grade) or ISO 12001:1996, accuracy grade 3 (survey grade), depending on the extent to which the requirements concerning the test environment are met.