NF EN ISO 717-1

Le présent document concerne les règles d'arrondi relatives aux indices et valeurs uniques. Il amende la norme homologuée NF EN ISO 717-1, d'août 1997. Les parties existantes de la NF EN ISO 717-1 et de la NF EN ISO 717-2 relatives à l'arrondi des données ne sont pas très précises et peuvent donner lieu à plusieurs interprétations, en particulier lors de leur mise en application numérique dans les logiciels informatiques. Le présent document donne des instructions plus précises.

<p>This document</p> <p>a) defines single-number quantities for airborne sound insulation in buildings and of building elements such as walls, floors, doors, and windows,</p> <p>b) takes into consideration the different sound level spectra of various noise sources such as noise sources inside a building and traffic outside a building, and</p> <p>c) gives rules for determining these quantities from the results of measurements carried out in one-third-octave or octave bands for example in accordance with ISO 10140-2 and ISO 16283-1.</p> <p>The single-number quantities in accordance with this document are intended for rating airborne sound insulation and for simplifying the formulation of acoustical requirements in building codes. An additional single-number evaluation in steps of 0,1 dB is indicated for the expression of uncertainty (except for spectrum adaptation terms). The required numerical values of the single-number quantities are specified according to varying needs. The single-number quantities are based on results of measurements in one-third-octave bands or octave bands.</p> <p>For laboratory measurements made in accordance with ISO 10140-2, single-number quantities are calculated using one-third-octave bands only.</p> <p>The rating of results of measurements carried out over an enlarged frequency range is dealt with in Annex B.</p>