DIN EN ISO 3743-1:2011-01

This standard describes a method of accuracy grade 2 (engineering grade) for determining the sound power level and sound energy level of a noise source from sound pressure measurements. The method is intended for hard-walled test rooms with prescribed acoustical characteristics, where it can be used for small items of portable equipment. It is based on a comparison of the sound pressure levels in octave frequency bands of a noise source under test with those of a calibrated reference sound source. A-weighted sound power levels or sound energy levels may be calculated from the octave-band levels. Requirements are specified, amongst other things, for the test room, background noise, instrumentation and installation and operation of the noise source under test; the measurements and calculations to be carried out are listed. The annexes describe the calculation of sound power and sound energy levels under meteorological reference conditions and of A-weighted levels from octave-band levels. Another annex contains a guideline on the development of information on measurement uncertainty. The most important alterations with respect to the 2009 edition of the standard are as follows: a) determination of sound energy levels has been added; b) treatment of measurement uncertainty has been extended and approach in accordance with the GUM Guide has been added; c) annex for the determination of sound power and sound energy levels under meteorological reference conditions has been added; d) annex with a guideline on the development of information on measurement uncertainty has been added; e) standard has been completely editorially revised. The international standard on which this standard is based has been prepared by Working Group 28 "Basic machinery noise emission standards" of ISO/TC 43/SC 1 "Noise" with German participation. On the European level, the standard exists within the framework of CEN/TC 211 "Acoustics". Regarding German cooperation, the responsible Working Committee is NA 001-01-04 AA "Geräuschemission von Maschinen und Anlagen: Messung, Minderung, Datensammlung" ("Noise emission of machines and plants: measurement, reduction, data collection") of NALS.