Acoustics - Laboratory measurement procedures for ducted silencers and air-terminal units - Insertion loss, flow noise and total pressure loss
Abstract
This document specifies methods for determining the insertion loss, in frequency bands, of ducted silencers with and without airflow, the sound power level, in frequency bands, of the flow noise (or regenerated sound) generated by ducted silencers, the total pressure loss of silencers with airflow, and the transmission loss, in frequency bands, of air-terminal units. The measurement procedures are intended for laboratory measurements at ambient temperature. Measurements on silencers in situ are specified in ISO 11820. The insertion loss measurements of ducted silencers without airflow are specified in ISO 11691. This document is applicable to silencers where the design velocity does not exceed 15 m/s. It is to be noted that the results determined in a laboratory according to this document will not necessarily be the same as those obtained in situ (installation), as different sound and flow fields will yield different results. For example, the pressure loss will be lower under laboratory conditions than in situ, but will be comparable between different laboratories. This document is applicable to all types of silencer including silencers for ventilating and air-conditioning systems, air intake and exhaust of flue gases, and similar applications. Other passive air-handling devices, such as bends, air-terminal units or T-connectors, can also be tested using this International Standard. This document is not applicable to reactive silencers used for motor vehicles.
Begin
2025-01-29
WI
00211218
Planned document number
DIN EN ISO 7235
Project number
00101194
Responsible national committee
NA 001-02-03 AA - Sound propagation, noise control and noise reduction
Responsible european committee
Responsible international committee
ISO/TC 43/SC 1/WG 58 - Sound power levels of air-terminal devices
