
Electroacoustics - Instruments for measurement of aircraft noise - Performance requirements for systems to measure sound pressure levels in noise certification of aircraft
STANDARD published on 8.5.2018
Designation standards: IEC 61265-ed.2.0
Publication date standards: 8.5.2018
The number of pages: 50
Approximate weight : 150 g (0.33 lbs)
Country: International technical standard
Category: Technical standards IEC
IEC 61265:2018 specifies requirements for the electroacoustical performance of systems of instruments used to measure sound for the purposes of aircraft noise certification, and for other comparisons among aircraft models, and provides methods by which tests can be made periodically to verify that the performance continues to conform to the requirements within stated limits. In general, a sound measurement system for this purpose comprises a combination of instruments extending from a microphone, including its windscreen and other accessories, through data recording and processing devices to a suitable output. Different measurement systems, regardless of their composition, perform the necessary functions in different ways and operate on either analogue or digital principles. IEC 61265:2018 cancels and replaces the first edition published in 1995. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: a) addition of guidance for measurements for aircraft other than large transport aeroplanes; b) addition of microphones used in ground plane measurement systems; c) addition of weighted sound level measurements other than one-third-octave band measurements, for certain aircraft types; d) revision and clarification of requirements for digital audio recording; e) addition of requirements for evaluation of measurement uncertainty. IEC 61265:2018 specifie les caracteristiques electroacoustiques des systemes instrumentaux utilises pour la mesure des bruits dans le cadre de la certification acoustique des aeronefs, ainsi que pour letablissement dautres comparaisons entre des modeles daeronefs, et fournit des methodes dessais de verification periodique qui permettent de sassurer du maintien des caracteristiques en conformite avec les exigences, a linterieur de tolerances specifiees. En general, un systeme de mesure utilise a cet effet se compose dune combinaison dinstruments allant du microphone, y compris son ecran anti-vent et ses autres accessoires, en passant par des dispositifs denregistrement et de traitement des donnees, jusqua un dispositif de sortie approprie. Les differents systemes de mesure, independamment de leur composition, realisent les fonctions necessaires de differentes facons et fonctionnent suivant des principes analogiques ou numeriques. IEC 61265:2018 annule et remplace la premiere edition parue en 1995. Cette edition constitue une revision technique. Cette edition inclut les modifications techniques majeures suivantes par rapport a ledition precedente: a) ajout de recommandations pour les mesures daeronefs autres que des gros avions de transport; b) ajout de microphones utilises dans les systemes de mesure a plan de sol; c) ajout de mesures de niveau acoustique pondere, autres que les mesures par bandes de tiers doctave, pour certains types daeronefs; d) revision et clarification des exigences applicables a lenregistrement audio numerique; e) ajout dexigences pour levaluation de lincertitude de mesure.