SIST-TS CEN/TS 16272-7:2015
(Main)Railway applications - Track - Noise barriers and related devices acting on airborne sound propagation - Test method for determining the acoustic performance - Part 7: Extrinsic characteristics - In situ values of insertion loss
Railway applications - Track - Noise barriers and related devices acting on airborne sound propagation - Test method for determining the acoustic performance - Part 7: Extrinsic characteristics - In situ values of insertion loss
This Technical Specification specifies methods for the determination of insertion loss of outdoor noise barriers intended to shield railway noise. It specifies detailed procedures for in situ measurement of barrier insertion loss including microphone positions, source conditions and acoustic environments of the measurement sites.
This Technical Specification allows one to measure the insertion loss of a given noise barrier at a given site including given meteorological conditions. It does not make it possible to compare insertion loss values of an equivalent barrier at a different site. It can be used for comparing insertion loss values of different types of barriers at the same site under given meteorological conditions by the "direct method".
This Technical Specification gives a method for determining insertion loss:
a) from the level difference before and after the installation of noise barriers (the "direct method") and when this is not possible because a barrier has already been installed;
b) using an indirect method to estimate the sound pressure levels before installation of the barrier by measurement at another site which has been judged to be equivalent.
For equivalent sites, a close match is required in source characteristics, microphone locations, terrain profiles ground surface characteristics, surrounding artificial structures and meteorological conditions. This Technical Specification prescribes principles for ensuring that sufficiently equivalent conditions are maintained between "before" and "after" cases to permit certain, reliable and repeatable determination of barrier insertion loss.
This Technical Specification does not cover the determination of the intrinsic acoustic characteristics of the barrier, for example the sound insulation index and the sound absorption coefficient.
The equivalent continuous A-weighted sound pressure level and one-third-octave band sound pressure level are used as noise descriptors.
This Technical Specification can be used for routine determination of barrier performance or for engineering or diagnostic evaluation. It can be used in situations where the barrier is to be installed or has already been installed.
Bahnanwendungen - Oberbau - Lärmschutzwände und verwandte Vorrichtungen zur Beeinflussung der Luftschallausbreitung - Prüfverfahren zur Bestimmung der akustischen Eigenschaften - Teil 7: Fremdspezifische Merkmale - In-situ-Werte zur Einfügungsdämpfung
Diese Technische Spezifikation legt Verfahren zur Bestimmung der Einfügungsdämpfung durch Lärmschutzwände im Freien fest, die zur Abschirmung von Schienenverkehrslärm vorgesehen sind. Sie legt detaillierte Verfahren zur In-situ-Messung der Einfügungsdämpfung von Lärmschutzwänden einschließlich Mikrofonpositionen, Schallquellenanforderungen und akustischen Umgebungen der Messorte fest.
Diese Technische Spezifikation ermöglicht die Messung der Einfügungsdämpfung einer gegebenen Lärmschutzwand an einem gegebenen Ort einschließlich der gegebenen Witterungsverhältnisse. Sie ermöglicht nicht den Vergleich von Einfügungsdämpfungswerten einer äquivalenten Lärmschutzwand an einem anderen Ort. Sie kann zum Vergleich von Einfügungsdämpfungswerten verschiedener Arten von Lärmschutzwänden am gleichen Ort bei gegebenen Witterungsverhältnissen durch das "direkte Verfahren" verwendet werden.
Diese Technische Spezifikation enthält ein Verfahren zur Bestimmung der Einfügungsdämpfung:
a) durch die Schallpegeldifferenz vor und nach der Installation von Lärmschutzwänden (das „direkte Verfahren“) und falls dies nicht möglich ist, weil bereits eine Lärmschutzwand errichtet wurde;
b) durch die Anwendung eines indirekten Verfahrens zur Schätzung des Schalldruckpegels vor der Installation der Lärmschutzwand durch Messung an einem anderen als gleichwertig befundenen Ort.
Bei äquivalenten Standorten ist eine hohe Übereinstimmung hinsichtlich der Eigenschaften der Schallquelle, Mikrofonpositionen, Geländeprofile, Bodenoberflächenbeschaffenheiten, umgebende Bauwerke und Witterungsverhältnisse erforderlich. Diese Technische Spezifikation schreibt Grundsätze vor, um sicherzustellen, dass ausreichend äquivalente Bedingungen zwischen "Vorher"- und "Nachher"-Messungen zur sicheren, zuverlässigen und wiederholbaren Bestimmung der Einfügungsdämpfung von Lärmschutzwänden beibehalten werden.
Diese Technische Spezifikation gilt nicht für die Bestimmung der intrinsischen akustischen Merkmale der Lärmschutzwand, wie z. B. den Schalldämmungsindex und den Schallabsorptionsgrad.
Der äquivalente A-bewertete Dauerschalldruckpegel und der Terzband-Schalldruckpegel werden dabei als Lärmdeskriptoren verwendet.
Diese Technische Spezifikation kann für die routinemäßige Bestimmung der Leistungsfähigkeit einer Lärmschutzwand oder zur Bewertung bei der technischen Planung oder der Diagnose verwendet werden. Sie kann in Situationen angewendet werden, in denen die Lärmschutzwand installiert werden soll oder bereits installiert wurde.
Applications ferroviaires - Voie - Dispositifs de réduction du bruit - Méthode d'essai pour la détermination des performances acoustiques - Partie 7 : Caractéristiques extrinsèques - Valeurs in situ de la perte par insertion
La présente Spécification technique prescrit des méthodes pour la détermination de la perte par insertion d’écrans antibruit en milieu extérieur, destinés à protéger du bruit ferroviaire. Elle indique des modes opératoires détaillés, relatifs au mesurage in situ de la perte par insertion d’un écran, y compris l’emplacement des microphones, les spécifications de la source et l’environnement acoustique des sites de mesure.
La présente Spécification technique permet de mesurer la perte par insertion d'un écran antibruit donné sur un site donné et dans des conditions météorologiques données. Elle ne permet pas de comparer les valeurs de la perte par insertion d’écrans équivalents sur des sites différents. En revanche, elle peut être utilisée pour comparer avec la « méthode directe », les valeurs de la perte par insertion de différents types d’écrans sur un même site et dans des conditions météorologiques données.
La présente Spécification technique présente une méthode pour la détermination de la perte par insertion :
a) à partir de la différence de niveau avant et après l’installation d’écrans antibruit (la « méthode directe ») et si c’est impossible, du fait qu’un écran a déjà été installé ;
b) en utilisant une méthode indirecte d’estimation des niveaux de pression acoustique avant l’installation de l’écran, par un mesurage sur un autre site considéré comme équivalent.
Pour que des sites soient équivalents, il faut une concordance étroite entre les caractéristiques des sources, l’emplacement des microphones, le profil du terrain, les caractéristiques de la surface du sol, les constructions environnantes et les conditions météorologiques. La présente Spécification technique préconise certains principes permettant de s’assurer que des conditions suffisamment équivalentes seront maintenues, avant et après, afin de pouvoir déterminer la perte par insertion d’un écran de façon répétitive et suffisamment fiable.
La détermination des caractéristiques acoustiques intrinsèques de l'écran, par exemple l'indice d'isolation acoustique et le coefficient d'absorption acoustique, n’est pas prise en compte par la présente Spécification technique.
Les indicateurs utilisés pour le bruit sont le niveau de pression acoustique équivalent continu pondéré A et le niveau de pression acoustique par bande de tiers d'octave.
La présente Spécification technique peut être utilisée pour la détermination courante de la performance de l’écran, ou dans le cadre d’un diagnostic ou d’une évaluation plus technique. Elle peut être utilisée lorsqu’un écran va être installé ou l’a déjà été.
Železniške naprave - Zgornji ustroj proge - Protihrupne ovire in pripadajoče naprave, ki vplivajo na širjenje zvoka po zraku - Preskusna metoda za ugotavljanje akustičnih lastnosti - 7. del: Zunanje značilnosti - Terenske vrednosti dodanega dušenja
Ta tehnična specifikacija določa metode za ugotavljanje dodanega dušenja hrupa protihrupnih ovir na prostem. Določa podrobne postopke za merjenje dodanega dušenja na terenu, vključno s položaji mikrofona, pogoji izvora hrupa in akustičnega okolja merilnih mest.
Ta tehnična specifikacija omogoča merjenje dodanega dušenja dane protihrupne ovire na določenem mestu, pri čemer se upoštevajo tudi vremenske razmere. Ne omogoča primerjave vrednosti dodanega dušenja z enakovredno oviro na drugem mestu. Lahko se uporablja za primerjavo vrednosti dodanega dušenja različnih vrst ovir na istem mestu v danih vremenskih razmerah z »neposredno metodo«.
Ta tehnična specifikacija podaja metodo za določanje dodanega dušenja:
a) iz razlike v ravni hrupa pred in po namestitvi protihrupne ovire (»neposredna metoda«), in če to ni mogoče, ker je bila ovira že nameščena;
b) s posredno metodo za oceno ravni zvočnega tlaka pred namestitvijo ovire z merjenjem na drugem, enakovrednem mestu.
Pri enakovrednih mestih je potrebno zagotoviti veliko podobnost v značilnostih vira, lokaciji mikrofona, profilu terena, značilnostih površine, umetnih strukturah v bližini in vremenskih razmerah. Ta tehnična specifikacija določa načela, s katerimi se zagotovi ohranjanje dovolj enakovrednih pogojev »prej« in »potem«, ki omogočajo nedvoumno, zanesljivo in ponovljivo določanje dodanega dušenja.
Ta tehnična specifikacija ne zajema določanja bistvenih akustičnih značilnosti ovire, na primer indeksa zvočne izolacije in koeficienta zvočne absorpcije.
Kot deskriptorji hrupa se uporabljajo A-vrednotena ekvivalentna neprekinjena raven zvočnega tlaka in zvočni tlak v frekvenčnih pasovih s širino tretjine oktave.
Ta tehnična specifikacija se lahko uporablja za rutinsko določanje učinkovitosti ovire ali za inženirsko oz. diagnostično oceno. Lahko se uporablja v primerih, ko ovira še ni nameščena in tudi če je že nameščena.
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
SIST-TS CEN/TS 16272-7:2015
01-december-2015
äHOH]QLãNHQDSUDYH=JRUQMLXVWURMSURJH3URWLKUXSQHRYLUHLQSULSDGDMRþH
QDSUDYHNLYSOLYDMRQDãLUMHQMH]YRNDSR]UDNX3UHVNXVQDPHWRGD]DXJRWDYOMDQMH
DNXVWLþQLKODVWQRVWLGHO =XQDQMH]QDþLOQRVWL7HUHQVNHYUHGQRVWLGRGDQHJD
GXãHQMD
Railway applications - Track - Noise barriers and related devices acting on airborne
sound propagation - Test method for determining the acoustic performance - Part 7:
Extrinsic characteristics - In situ values of insertion loss
Bahnanwendungen - Oberbau - Lärmschutzwände und verwandte Vorrichtungen zur
Beeinflussung der Luftschallausbreitung - Prüfverfahren zur Bestimmung der
akustischen Eigenschaften - Teil 7: Fremdspezifische Merkmale - In-situ-Werte zur
Einfügungsdämpfung
Applications ferroviaires - Voie - Dispositifs de réduction du bruit - Méthode d'essai pour
la détermination des performances acoustiques - Partie 7 : Caractéristiques extrinsèques
- Valeurs in situ de la perte par insertion
Ta slovenski standard je istoveten z: CEN/TS 16272-7:2015
ICS:
17.140.30 Emisija hrupa transportnih Noise emitted by means of
sredstev transport
93.100 Gradnja železnic Construction of railways
SIST-TS CEN/TS 16272-7:2015 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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CEN/TS 16272-7
TECHNICAL SPECIFICATION
SPÉCIFICATION TECHNIQUE
September 2015
TECHNISCHE SPEZIFIKATION
ICS 93.100
English Version
Railway applications - Track - Noise barriers and related
devices acting on airborne sound propagation - Test
method for determining the acoustic performance - Part 7:
Extrinsic characteristics - In situ values of insertion loss
Applications ferroviaires - Voie - Dispositifs de Bahnanwendungen - Oberbau - Lärmschutzwände und
réduction du bruit - Méthode d'essai pour la verwandte Vorrichtungen zur Beeinflussung der
détermination des performances acoustiques - Partie 7 Luftschallausbreitung - Prüfverfahren zur Bestimmung
: Caractéristiques extrinsèques - Valeurs in situ de la der akustischen Eigenschaften - Teil 7:
perte par insertion Fremdspezifische Merkmale - In-situ-Werte zur
Einfügungsdämpfung
This Technical Specification (CEN/TS) was approved by CEN on 17 August 2015 for provisional application.
The period of validity of this CEN/TS is limited initially to three years. After two years the members of CEN will be requested to
submit their comments, particularly on the question whether the CEN/TS can be converted into a European Standard.
CEN members are required to announce the existence of this CEN/TS in the same way as for an EN and to make the CEN/TS
available promptly at national level in an appropriate form. It is permissible to keep conflicting national standards in force (in
parallel to the CEN/TS) until the final decision about the possible conversion of the CEN/TS into an EN is reached.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2015 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TS 16272-7:2015 E
worldwide for CEN national Members.
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Contents Page
European foreword . 4
Introduction . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 7
4 Symbols and abbreviations . 9
5 Methods . 10
5.1 General . 10
5.2 Direct measurement method . 10
5.3 Indirect measurement method . 10
6 Instrumentation . 10
6.1 Sound level meter and analyzer . 10
6.2 Sound calibrator . 10
6.3 Windscreen . 11
6.4 Other instrumentation system . 11
6.5 Meteorological equipment . 11
7 Acoustic environment . 11
7.1 General . 11
7.2 Terrain profile and ground surface equivalence . 11
7.3 Meteorological conditions . 12
7.3.1 General . 12
7.3.2 Wind . 12
7.3.3 Temperature . 13
7.3.4 Humidity . 13
7.3.5 Cloud cover . 13
7.3.6 Others . 14
7.3.7 Background noise . 14
8 Sources and source equivalence . 14
8.1 Source type . 14
8.1.1 General . 14
8.1.2 Source type A . 14
8.1.3 Source type B . 14
8.1.4 Source type C . 14
8.2 Source equivalence . 15
8.2.1 General . 15
8.2.2 Operational parameters . 16
8.2.3 Reference microphone position . 16
9 Measurement procedure . 17
9.1 General planning . 17
9.1.1 Measurement . 17
9.1.2 Receiver positions. 17
9.1.3 Quantities to be measured . 17
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9.2 Determination of barrier insertion loss . 18
9.2.1 Direct measurement method . 18
9.2.2 Indirect measurement method . 18
10 Measurement uncertainty . 19
11 Test report . 19
11.1 Information to be recorded. 19
11.1.1 Type of method . 19
11.1.2 Instrumentation . 19
11.1.3 Acoustic environment . 19
11.1.4 Sound source . 19
11.1.5 Barrier to be tested . 19
11.1.6 Site layout . 19
11.1.7 Acoustical data . 20
11.2 Expression of results . 20
11.3 Further information . 20
Annex A (informative) Measurement uncertainty . 21
A.1 General . 21
A.2 Measurement uncertainty based upon reproducibility data . 21
Bibliography . 22
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European foreword
This document (CEN/TS 16272-7:2015) has been prepared by Technical Committee CEN/TC 256
“Railway applications”, the secretariat of which is held by DIN.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent
rights.
This Technical Specification is one of the series EN 16272, Railway applications — Track — Noise
barriers and related devices acting on airborne sound propagation — Test method for determining the
acoustic performance, as listed below:
— Part 1: Intrinsic characteristics — Sound absorption in the laboratory under diffuse sound field
conditions;
— Part 2: Intrinsic characteristics — Airborne sound insulation in the laboratory under diffuse sound
field conditions;
— Part 3-1: Normalized railway noise spectrum and single number ratings for diffuse field applications;
— Part 3-2: Normalized railway noise spectrum and single number ratings for direct field applications;
— Part 4: Intrinsic characteristics — In situ values of sound diffraction under direct sound field
conditions [currently at Enquiry stage];
— Part 5: Intrinsic characteristics — In situ values of sound reflection under direct sound field
conditions;
— Part 6: Intrinsic characteristics — In situ values of airborne sound insulation under direct sound field
conditions;
— Part 7: Extrinsic characteristics — In situ values of insertion loss [the present document].
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to announce this Technical Specification: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
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Introduction
The purpose of insertion loss measurements is to have an indication of the “efficiency” of the complete
installation in attenuating noise from a technical point of view, as is usually done with calculations. The
insertion loss is not intended to compare products; in fact, it is site-dependent, so that the same product
may give different results when installed on different sites.
In order to be representative, these measurements need to be done in well-defined conditions
regarding:
— the noise source (number and type of trains, speed, etc.);
— the meteorological window;
— the measurement time;
— the reference time, i.e. the time over which the measured insertion loss is evaluated based on the
measurement results.
When it is not possible to carry out measurements before the construction of the noise barrier, an
“equivalent” site is used for the “before” measurements.
The assessment of insertion loss limiting values is out of the scope of this Technical Specification.
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1 Scope
This Technical Specification specifies methods for the determination of insertion loss of outdoor noise
barriers intended to shield railway noise. It specifies detailed procedures for in situ measurement of
barrier insertion loss including microphone positions, source conditions and acoustic environments of
the measurement sites.
This Technical Specification allows one to measure the insertion loss of a given noise barrier at a given
site including given meteorological conditions. It does not make it possible to compare insertion loss
values of an equivalent barrier at a different site. It can be used for comparing insertion loss values of
different types of barriers at the same site under given meteorological conditions by the “direct
method”.
This Technical Specification gives a method for determining insertion loss:
a) from the level difference before and after the installation of noise barriers (the “direct method”);
b) when the direct method is not applicable, because a barrier has already been installed, using an
"indirect method" to estimate the sound pressure levels before installation of the barrier by
measurement at another site which has been judged to be equivalent.
For equivalent sites, a close match is required in source characteristics, microphone locations, terrain
profiles ground surface characteristics, surrounding artificial structures and meteorological conditions.
This Technical Specification prescribes principles for ensuring that sufficiently equivalent conditions
are maintained between “before” and “after” cases to permit certain, reliable and repeatable
determination of barrier insertion loss.
This Technical Specification does not cover the determination of the intrinsic acoustic characteristics of
the barrier, for example the sound insulation index and the sound absorption coefficient.
The equivalent continuous A-weighted sound pressure level and one-third-octave band sound pressure
level are used as noise descriptors.
This Technical Specification can be used for routine determination of barrier performance or for
engineering or diagnostic evaluation. It can be used in situations where the barrier is to be installed or
has already been installed.
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.
EN 60942, Electroacoustics — Sound calibrators (IEC 60942)
EN 61260, Electroacoustics — Octave-band and fractional-octave-band filters (IEC 61260)
EN 61672-1, Electroacoustics — Sound level meters — Part 1: Specifications (IEC 61672-1)
ISO/IEC Guide 98-3, Uncertainty of measurement — Part 3: Guide to the expression of uncertainty in
measurement (GUM:1995)
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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 and which will typically span between posts and also may overhang the railway
Note 1 to entry: Noise barriers are generally made of acoustic and structural elements (see 3.3 and 3.4).
3.2
cladding
noise reducing device, which is attached to a wall or other structure and reduces the amount of sound
reflected
Note 1 to entry: Claddings are generally made of acoustic and structural elements (see 3.3 and 3.4).
3.3
acoustic element
element whose primary function is to provide the acoustic performance of the device
3.4
structural element
element whose primary function is to support or hold in place acoustic elements
3.5
added device
added component that influences the acoustic performance of the original noise-reducing device (acting
primarily on the diffracted energy)
Note 1 to entry: In some noise barriers, the acoustic function and the structural function cannot be clearly
separated and attributed to different components.
3.6
sound pressure level
L
p
ten times the logarithm to the base 10 of the ratio of the square of the sound pressure to the square of
the reference sound pressure, in decibels
Note 1 to entry: The reference sound pressure is 20 μPa. The frequency weighting or the width of the frequency
band used will be indicated.
3.7
equivalent continuous sound pressure level
L
peqT
sound pressure level, in decibels, of a continuous steady sound that, within a measurement time
interval T , has the same mean-square sound pressure as a sound under consideration whose level
p
varies with time, and that is given by the following formula:
t
2 2
1 pt()
L =10lg dt dB (1)
peq,T
2
p ∫
Tp
p t 0
1
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where
t and t are times corresponding to the beginning and end of the train pass-by time interval, or the
1 2
measurement duration in the case of source Type C (loudspeaker);
T = t - t ;
p 2 1
p(t) is an instantaneous sound pressure;
p is the reference sound pressure (20 μPa)
0
Note 1 to entry: The frequency weighting or the width of the frequency band used is to be indicated; for
example, equivalent continuous A-weighted sound pressure level L , equivalent continuous one-third-octave
pAeqT
band sound pressure level, etc.
3.8
insertion loss of barriers
D
IL
difference, in decibels, in sound pressure levels at a specified receiver position before and after the
installation of a barrier provided that the noise source, terrain profiles, interfering obstructions and
reflecting surfaces, if any, ground and meteorological conditions have not changed
Note 1 to entry: The frequency weighting or the width of frequency band and the time weighting used need to
be indicated; for example, insertion loss of barrier corresponding to equivalent continuous A-weighted sound
pressure levels (D ).
ILA
3.9
background noise level
sound pressure level, in decibels, at a reference position or receiver position without any noise source
in operation
3.10
source position
point at which the source is located (for stationary source), an area in which sources are located or
move (for stationary and mobile sources), or a line along which sources are located or move (for
stationary and mobile sources)
3.11
reference position
point at which the sound from the source is, or will be, minimally influenced by the installed barrier or
planned barrier
Note 1 to entry: The reference position will be used to monitor the source level.
3.12
receiver position
point at which an insertion loss is to be determined
3.13
far field
region in which the sound pressure level for a simple point source decays six decibels per doubling of
distance and, for an incoherent line source, three decibels per doubling of distance, without ground
attenuation
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3.14
train pass-by time period
time interval during which a train is passing in front of a location; it is equal to the time window
between the instant t when the train nose passes in front of the location, and the instant t when the
1 2
tail of the train passes in front of the same location
Note 1 to entry: The initial and final time instants of the train pass-by time interval can be detected by optical
devices.
Note 2 to entry: The pass-by time window is given by Formula (2):
L
T =36, (2)
p
v
where
L is the train length in metres;
v is the train speed in km/h
4 Symbols and abbreviations
For the purposes of this document, the following symbols and abbreviations apply.
Table 1 — Symbols and abbreviations
Symbol or
Designation Unit
abbreviation
L equivalent continuous sound pressure level during the train pass-by time interval dB
peq,Tp
D insertion loss of barriers dB
IL
H source height m
S
H receiver height m
R
H barrier height m
B
d horizontal distance between source and barrier m
1
d horizontal distance between barrier and receiver m
2
t initial instant of the train pass-by time interval s
1
t final instant of the train pass-by time interval s
2
T train pass-by time interval s
p
L train length m
v train speed km/h
Lref,B “before” sound pressure level at the reference position dB
L “before” sound pressure level at the receiver position dB
r,B
L “after” sound pressure level at the reference position dB
ref,A
L “after” sound pressure level at the receiver position dB
r,A
C correction factors for “hemi free-field” at receiver position dB
r
C’ correction factors for “on reflecting surfaces” at receiver position dB
r
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CEN/TS 16272-7:2015 (E)
5 Methods
5.1 General
This Technical Specification specifies two methods for the determination of insertion loss of outdoor
noise barriers. The recommended method is the direct method. The alternative method is the indirect
measurement method using measured “before” levels at an equivalent site.
The method to be adopted is chosen by considering several factors including the objectives of the
measurement, the ability to make measurements prior to barrier installation, and the feasibility of
equivalence of source, terrain profile, interfering obstructions and reflecting surfaces, if any, ground
surface and meteorological conditions.
5.2 Direct measurement method
The direct method can only be used if the barrier has not yet been installed or can be removed for the
“before” measurements. The sound pressure levels are measured at the reference and receiver
positions for both “before” and “after” barrier installations. The same reference and receiver positions
shall be used in both the “before” and “after” cases. Equivalence shall be established for sources, terrain
profiles, interfering obstructions and reflecting surfaces, if any, ground surface and meteorological
conditions.
5.3 Indirect measurement method
If the barrier has been installed and it cannot be readily removed to permit direct “before”
measurement, an estimated “before” sound pressure level is obtained by measurement at a site that is
equivalent to the study site.
Site equivalence refers to equivalence of the source, the terrain profiles, interfering obstructions and
reflecting surfaces, if any, ground surface and meteorological conditions.
6 Instrumentation
6.1 Sound level meter and analyzer
Integrating averaging sound level meters meeting type 1 requirements of EN 61672-1 shall be used.
The measurement uncertainty shall always be estimated. In addition, a periodic verification of the
instrumentation system shall be carried out in order to verify the conformity to the relevant
specification standards. The interval between verifications shall be determined by the national
standards or regulations in respective countries. At the beginning of the measurements, and following
any warm-up time specified by the manufacturer, the overall sensitivity of the sound level meter shall
be checked using a sound calibrator conforming to EN 60942. If necessary, it shall be adjusted according
to the manufacturer’s instructions. A further check shall be performed at the end of each measurement
session. At least two measurement channels shall be used to permit simultaneous measurements at a
reference and receiver position.
One-third-octave band filter sets, if used, shall meet the requirements of EN 61260.
6.2 Sound calibrator
A sound calibrator meeting the requirements of EN 60942 shall be used.
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SIST-TS CEN/TS 16272-7:2015
CEN/TS 16272-7:2015 (E)
6.3 Windscreen
A windscreen as recommended by the manufacturer shall be used on each microphone during
measurements.
6.4 Other instrumentation system
If other measurement systems are used, such as analogue or digital recorders or digital data acquisition
systems, the system shall be verified to ensure it meets the requirements of the EN standards
referenced above. The uncertainties associated with the use of the system shall be evaluated.
6.5 Meteorological equipment
An anemometer or other device for measuring wind speed and wind direction shall
...
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