DIN EN ISO 3741:2009 Acoustics - Determination of sound power levels of noise sources using sound pressure - Precision methods for reverberation rooms (ISO 3741:1999, including Cor 1:2001); English version of DIN EN ISO 3741:2009-11
1.1 This International Standard specifies a direct method and a comparison method for determining the sound
power level that would be produced by a source operating in an environment at standard meteorological conditions
corresponding to a characteristic impedance of pc= 400 N.s/m3 (where p is the density of air and c is the speed of
sound). It specifies test room requirements, source location and general rules for operating conditions,
instrumentation and techniques for obtaining an estimate of mean-square sound pressure levels from which the
sound power levels of the source in octave or one-third-octave bands are calculated with a grade 1 accuracy. The
quantities to be measured are time-averaged sound pressure levels in frequency bands. The quantities to be
determined are sound power levels, A-weighted and in frequency bands. Other quantities, which are optional, are
sound power levels with other frequency weightings calculated from the measurements in frequency bands. This
standard does not provide the means to determine directivity and temporal variation of sound from a source.
In general, the frequency range of interest includes the one-third-octave bands with midband frequencies from
100 Hz to 10 000 Hz. Guidelines for the application of the specified methods in an extended frequency range in
respect to lower frequencies are given in annex C. This International Standard is not applicable to frequency ranges
above the 10 O00 Hz one-third-octave band. For higher frequencies the use of methods given in ISO 9295 is
recommended.
1.2 The method specified in this International Standard is suitable for steady noise with broad-band, narrow-band
and discrete-frequency components as described in ISO 12001. The noise may be emitted from a device, machine,
component or sub-assembly.
This International Standard is applicable to noise sources with volumes which are preferably not greater than 2 % of
the volume of the reverberation room used for the test. For sources with volumes greater than 2 % of the room
volume, the standard deviations given by Table 2 could be exceeded.
DIN EN ISO 3741:2009 history
2011DIN EN ISO 3741:2011 Acoustics - Determination of sound power levels and sound energy levels of noise sources using sound pressure - Precision methods for reverberation test rooms (ISO 3741:2010); German version EN ISO 3741:2010
2009DIN EN ISO 3741:2009 Acoustics - Determination of sound power levels of noise sources using sound pressure - Precision methods for reverberation rooms (ISO 3741:1999, including Cor 1:2001); English version of DIN EN ISO 3741:2009-11
2002DIN EN ISO 3741 Berichtigung 1:2002 Acoustics – Determination of the sound power levels of noise sources through sound pressure measurements – Reverberation room method of accuracy class 1
2001DIN EN ISO 3741:2001 Acoustics Determination of the sound power levels of noise sources from sound pressure measurements using reverberation chamber methods of accuracy class 1