BS EN 16272-1-2012 pdf download.Railway applications Track Noise barriers and related
devices acting on airborne sound propagation Test method for determining the acoustic performance Part 1: Intrinsic characteristics — Sound absorption in the laboratory under diffuse sound field conditions.
This BS EN 16272-1 specifies the laboratory method for measuring the sound absorption of flat noise barriers or flat claddings for retaining walls or tunnels. It covers the assessment of the intrinsic sound absorption performance of noise barriers and related devices acting on airborne sound propagation designed for railways which can reasonably be assembled inside the testing facility described in EN ISO 354, The test method in EN ISO 354, referred to in this European Standard, is strictly valid only for flat absorbers and in particular excludes devices which act as slightly damped resonators. Some devices will depart significantly from these requirements and in these cases care is needed in interpreting the results.
All noise reducing devices that differ from noise barriers and related devices acting on airborne sound propagation, e.g. devices for attenuation of ground borne vibration and on board devices are out of the scope of this European Standard.
NOTE The test method in EN ISO 354 is based on measurements m a reverberation room where diffuse sound field conditions prevail. As a uniformly applicable method for the determination of the sound absorptive performance of noise reducing devices under free field conditions is still under development, the measurement results according to this European Standard are temporarily considered relevant for application on noise reducing devices in reverberant as well as in free field conditions.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ENV 13005, Guide to the expression of uncertainty in measurement
EN 16272-3-1, Railway applications — Track — Noise barriers and related devices acting on airborne sound propagation — Test method for determining the acoustic performance — Part 3-i: Normalised railway noise spectrum and single number ratings for diffuse field applications
EN ISO 354, Acoustics — Measurement of sound absorption in a reverberation room (ISO 354)
3 Terms and definitions
For the purpose of this document the following terms and definitions apply.
3.1
noise barrier
noise reducing device, which obstructs the direct transmission of airborne sound emanating from railways; it may either span or overhang the railway
Note 1 to entry: Noise barriers are generally made of acoustic and structural elements (see 3.3 and 3.4).
5 Test arrangement
The test arrangement shall be as described in EN ISO 354, with the following modifications:
a) The test specimen shall be assembled in the test chamber in the same manner as the manufactured device is used in practice, with the same connections and seals between the component parts.
b) All the reflecting parts exposed on the rail side of the material (posts, brackets and other parts) shall be present on the specimen as in practice.
C) Where posts are employed In construction, at least one post shall be included in the specimen with panels attached on both sides. The length of the panels on one side of the post shall be L  2 m (see Figure 1 and Figure 2). The side that would face the rail shall face the inner part of the room (see Figure 1 and Figure 2). The post shall be sealed as In practice.
d) The test specimen shall have a reflecting frame sealed against it on its entire perimeter (see Figure 1 to Figure 5).
e) For testing noise barriers, the specimen shall be placed directly against one of the surfaces (floor, wall or ceiling) of the chamber without any gap (see Figure 1, Figure 2 and Figure 3). If needed, concrete, used as filler, shall be inserted between panels and chamber surface.
f) If the sample under test Includes non flat panels, leaving cavities between the panels and the chamber floor, these cavities should be completely filled with concrete (see Figure 3).
9) If the sample under test includes a post it is recommended to cut it to fit the panel thickness.
h) If the sample under test includes a post having a thickness larger than that of the acoustic elements and protruding toward the interior of the test chamber, the reflective area created by the post fitting the acoustic elements shall be reproduced covering it by reflective strips (see Figure 4).
I) If the sample under test includes a post having a thickness larger than that of the acoustic elements and protruding toward the floor of the test chamber, the cavities created by the post under the acoustic elements shall be completely filled with concrete (see Figure 5).BS EN 16272-1-2012 pdf download.