SIST EN ISO 15186-2:2010

Acoustics - Measurement of sound insulation in buildings and of building elements using sound intensity - Part 2: Field measurements (ISO 15186-2:2003)

ISO 15186-2:2003 specifies a sound intensity method to determine the in-situ sound insulation of walls, floors, doors, windows and small building elements. It is intended for measurements that have to be made in the presence of flanking transmission. It can be used to provide sound power data for diagnostic analysis of flanking transmission or to measure flanking sound insulation parameters.
ISO 15186-2:2003 can be used by laboratories that could not satisfy the requirements of ISO 15186-1, which deals with laboratory measurements with no or little flanking transmission. ISO 15186-3 deals with measurements under laboratory conditions, at low frequencies.
ISO 15186-2:2003 also describes the effect of flanking transmission on measurements made using the specified method, and how intensity measurements can be used
-- to compare the in-situ sound insulation of a building element with laboratory measurements where flanking has been suppressed (i.e. ISO 140-3),
-- to rank the partial contributions for building elements, and
-- to measure the flanking sound reduction index for one or more transmission paths (for validation of prediction models such as those given in EN 12354-1).
This method gives values for airborne sound insulation, which are frequency dependent. They can be converted into a single number, characterizing the acoustic performance, by application of ISO 717-1.
The reproducibility of this intensity method is estimated to be equal to or better than that of the methods of ISO 140-10 and ISO 140-4, when measuring a single small and large building element, respectively.

Akustik - Bestimmung der Schalldämmung in Gebäuden und von Bauteilen aus Schallintensitätsmessungen - Teil 2: Messungen am Bau (ISO 15186-2:2003)

1 Anwendungsbereich
1.1 Allgemeines
Der vorliegende Teil von ISO 15186 legt ein Schallintensitätsverfahren zur Bestimmung der Schalldämmung
von Wänden, Fußböden, Fenstern und kleinen Bauteilen durch Messungen am Bau fest. Das Verfahren ist für
Messungen vorgesehen, die bei vorhandener Flankenübertragungen erfolgen müssen. Es kann eingesetzt
werden, um Schallleistungsdaten zur Diagnose von Flankenübertragungen zu ermitteln oder um Parameter
der Flankenschalldämmung zu messen.
Dieser Teil von ISO 15186 kann in Prüfständen angewendet werden, die die Anforderungen von ISO 15186-1,
in welcher Prüfstandmessungen ohne oder mit nur sehr geringer Flankenübertragung behandelt sind, nicht
erfüllen. ISO 15186-3 behandelt Messungen unter Prüfstandbedingungen bei tiefen Frequenzen.
Der vorliegende Teil von ISO 15186 beschreibt außerdem die Wirkung von Flankenübertragungen auf mit
dem festgelegten Verfahren durchgeführte Messungen und die Art und Weise, in der die Intensitätsmessungen
genutzt werden können, um
- die vor Ort vorliegende Schalldämmung eines Bauteils mit Prüfstands-Messungen mit unterdrückter
Flankenübertragung (z. B. ISO 140-3) zu vergleichen,
- Bauteile in Hinblick auf den Anteil an der Schalltransmission zu reihen,
- das Flanken-Schalldämm-Maß für einen oder mehrere Übertragungswege zu messen (zur Validierung
der z. B. in EN 12354-1 angegebenen Vorhersagemodelle).
Dieses Verfahren gibt frequenzabhängige Werte für die Luftschalldämmung an. Diese Werte können unter
Anwendung von ISO 717-1 in Einzahlangaben umgerechnet werden, die die akustischen Eigenschaften
charakterisieren.
1.2 Präzision
Die Vergleichpräzision dieses Intensitätsverfahrens ist bei Messung an einem einzelnen kleinen oder großen
Bauteil schätzungsweise gleich oder besser als die der Verfahren aus ISO 140-10 und ISO 140-4.

Acoustique - Mesurage par intensité de l'isolation acoustique des immeubles et des éléments de construction - Partie 2: Mesurages in situ (ISO 15186-2:2003)

L'ISO 15186-2:2003 spécifie une méthode d'intensité acoustique pour déterminer l'isolement acoustique in situ des murs, des sols, des portes, des fenêtres et des petits éléments de construction. Elle est destinée aux mesurages devant être réalisés en présence de transmissions latérales. Elle peut être utilisée pour fournir des données relatives à la puissance acoustique en vue d'une analyse des transmissions latérales ou pour mesurer les paramètres d'isolement acoustique latéral.
L'ISO 15186-2:2003 peut être utilisée par les laboratoires n'ayant pu répondre aux exigences de l'ISO 15186‑1, qui traite des mesurages en laboratoire sans ou quasi-sans transmission latérale. L'ISO 15186‑3 couvre les mesurages effectués dans des conditions de laboratoire, aux basses fréquences.
L'ISO 15186-2:2003 décrit également l'effet des transmissions latérales sur les mesurages réalisés à l'aide de la méthode spécifiée, et explique comment utiliser les mesurages d'intensité pour établir une comparaison entre l'isolement acoustique in situ d'un élément de construction et les mesurages de laboratoire pour lesquels les transmissions latérales ont été supprimées (ISO 140‑3); pour établir un classement des contributions partielles des éléments de construction; et pour mesurer l'indice d'affaiblissement acoustique latéral pour un ou plusieurs chemins de transmission (en vue de valider des modèles de prévision, tels que ceux donnés dans l'EN 12354‑1).
Cette méthode donne des valeurs d'isolement aux bruits aériens, qui sont dépendantes des fréquences. Elles peuvent être converties en un indice unique qui caractérise la performance acoustique, par application de l'ISO 717‑1.

Akustika - Merjenje zvočne izolirnosti v stavbah in zvočne izolirnosti gradbenih elementov z uporabo zvočne intenzitete - 2. del: Terenska merjenja (ISO 15186-2:2003)

Ta del ISO 15186 določa metodo zvočne intenzitete za določevanje in situ zvočne izolirnosti sten, tal, vrat, oken in majhnih gradbenih elementov. Namenjen je za merjenja, ki morajo biti izvedena v prisotnosti bočnega prenosa. Lahko se uporablja za zagotavljanje podatkov o moči zvoka za diagnostično analizo bočnega prenosa ali za merjenje parametrov izolirnosti pred bočnim prenosom zvoka. Ta del ISO 15186 lahko uporabljajo laboratoriji, ki niso mogli izpolniti pogojev ISO 15186-1, kateri obravnava laboratorijska merjenja brez ali z majhnim bočnim prenosom. ISO 15186-3 obravnava merjenja pod laboratorijskimi pogoji, pri nizkih frekvencah.

General Information

• Status: Published
• Public Enquiry End Date: 19-May-2010
• Publication Date: 15-Nov-2010
• ICS: 17.140.01 - Acoustic measurements and noise abatement in general
• ICS: 91.120.20 - Acoustics in building. Sound insulation
• Technical Committee: AKU - Acoustics
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 18-Oct-2010
• Due Date: 23-Dec-2010
• Completion Date: 16-Nov-2010
• Ref Project: EN ISO 15186-2:2010 - Acoustics - Measurement of sound insulation in buildings and of building elements using sound intensity - Part 2: Field measurements (ISO 15186-2:2003)

Standards Content (Sample)

SLOVENSKI STANDARD
01-december-2010
$NXVWLND0HUMHQMH]YRþQHL]ROLUQRVWLYVWDYEDKLQ]YRþQHL]ROLUQRVWLJUDGEHQLK
HOHPHQWRY]XSRUDER]YRþQHLQWHQ]LWHWHGHO7HUHQVNDPHUMHQMD,62

Acoustics - Measurement of sound insulation in buildings and of building elements using
sound intensity - Part 2: Field measurements (ISO 15186-2:2003)
Akustik - Bestimmung der Schalldämmung in Gebäuden und von Bauteilen aus
Schallintensitätsmessungen - Teil 2: Messungen am Bau (ISO 15186-2:2003)
Acoustique - Mesurage par intensité de l'isolation acoustique des immeubles et des
éléments de construction - Partie 2: Mesurages in situ (ISO 15186-2:2003)
Ta slovenski standard je istoveten z: EN ISO 15186-2:2010
ICS:
17.140.01 $NXVWLþQDPHUMHQMDLQ Acoustic measurements and
EODåHQMHKUXSDQDVSORãQR noise abatement in general
91.120.20 $NXVWLNDYVWDYEDK=YRþQD Acoustics in building. Sound
L]RODFLMD insulation
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN ISO 15186-2
NORME EUROPÉENNE
EUROPÄISCHE NORM
September 2010
ICS 91.120.20
English Version
Acoustics - Measurement of sound insulation in buildings and of
building elements using sound intensity - Part 2: Field
measurements (ISO 15186-2:2003)
Acoustique - Mesurage par intensité de l'isolation Akustik - Bestimmung der Schalldämmung in Gebäuden
acoustique des immeubles et des éléments de construction und von Bauteilen aus Schallintensitätsmessungen - Teil 2:
- Partie 2: Mesurages in situ (ISO 15186-2:2003) Messungen am Bau (ISO 15186-2:2003)
This European Standard was approved by CEN on 5 August 2010.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national
standards may be obtained on application to the CEN Management Centre or to any CEN member.

This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as the
official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland,
Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2010 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 15186-2:2010: E
worldwide for CEN national Members.

Contents Page
Foreword .3

Foreword
The text of ISO 15186-2:2003 has been prepared by Technical Committee ISO/TC 43 “Acoustics” of the
International Organization for Standardization (ISO) and has been taken over as EN ISO 15186-2:2010 by
Technical Committee CEN/TC 126 “Acoustic properties of building elements and of buildings” the secretariat
of which is held by AFNOR.
This European Standard shall be given the status of a national standard, either by publication of an identical
text or by endorsement, at the latest by March 2011, and conflicting national standards shall be withdrawn at
the latest by March 2011.
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.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.
Endorsement notice
The text of ISO 15186-2:2003 has been approved by CEN as a EN ISO 15186-2:2010 without any
modification.
INTERNATIONAL ISO
STANDARD 15186-2
First edition
2003-06-01
Acoustics — Measurement of sound
insulation in buildings and of building
elements using sound intensity —
Part 2:
Field measurements
Acoustique — Mesurage par intensité de l'isolation acoustique des
immeubles et des éléments de construction —
Partie 2: Mesurages in situ
Reference number
ISO 15186-2:2003(E)
©
ISO 2003
ISO 15186-2:2003(E)
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ii © ISO 2003 — All rights reserved

ISO 15186-2:2003(E)
Contents Page
Foreword. iv
1 Scope. 1
2 Normative references . 2
3 Terms and definitions. 2
4 Instrumentation . 7
5 Test arrangement . 8
6 Test procedure . 9
7 Expression of results. 14
8 Test report. 15
Annex A (normative) Adaptation term K . 16
c
Annex B (informative) Estimated precision and bias of the method. 17
Annex C (informative) Measurement and the effect of flanking transmission. 21
Bibliography . 25

ISO 15186-2:2003(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 15186-2 was prepared by Technical Committee ISO/TC 43, Acoustics, Subcommittee SC 2, Building
acoustics.
ISO 15186 consists of the following parts, under the general title Acoustics — Measurement of sound
insulation in buildings and of building elements using sound intensity:
 Part 1: Laboratory measurements
 Part 2: Field measurements
 Part 3: Laboratory measurements at low frequencies

iv © ISO 2003 — All rights reserved

INTERNATIONAL STANDARD ISO 15186-2:2003(E)

Acoustics — Measurement of sound insulation in buildings and
of building elements using sound intensity —
Part 2:
Field measurements
1 Scope
1.1 General
This part of ISO 15186 specifies a sound intensity method to determine the in-situ sound insulation of walls,
floors, doors, windows and small building elements. It is intended for measurements that have to be made in
the presence of flanking transmission. It can be used to provide sound power data for diagnostic analysis of
flanking transmission or to measure flanking sound insulation parameters.
This part of ISO 15186 can be used by laboratories that could not satisfy the requirements of ISO 15186-1,
which deals with laboratory measurements with no or little flanking transmission. ISO 15186-3 deals with
measurements under laboratory conditions, at low frequencies.
This part of ISO 15186 also describes the effect of flanking transmission on measurements made using the
specified method, and how intensity measurements can be used
 to compare the in-situ sound insulation of a building element with laboratory measurements where
flanking has been suppressed (i.e. ISO 140-3),
 to rank the partial contributions for building elements, and
 to measure the flanking sound reduction index for one or more transmission paths (for validation of
prediction models such as those given in EN 12354-1).
This method gives values for airborne sound insulation, which are frequency dependent. They can be
converted into a single number, characterizing the acoustic performance, by application of ISO 717-1.
1.2 Precision
The reproducibility of this intensity method is estimated to be equal to or better than that of the methods of
ISO 140-10 and ISO 140-4, when measuring a single small and large building element, respectively.
NOTE 1 If sound reduction measures made using this method are to be compared with those made using the
conventional reverberation room method in various parts of ISO 140, then it will be necessary to introduce an adaptation
term that reflects the bias between the test methods. This term is given in Annex A.
NOTE 2 Some information about the accuracy for this part of ISO 15186 and its relationship to the sound reduction
index measured according to ISO 140-3 and ISO 140-4 is given in Annex B.
NOTE 3 Flanking transmission is discussed in Annex C.
ISO 15186-2:2003(E)
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO 140-3:1995, Acoustics — Measurement of sound insulation in buildings and of building elements —
Part 3: Laboratory measurements of airborne sound insulation of building elements
ISO 140-4:1995, Acoustics — Measurement of sound insulation in buildings and of building elements —
Part 4: Field measurements of airborne sound insulation between rooms
ISO 140-10:1991, Acoustics — Measurement of sound insulation in buildings and of building elements —
Part 10: Laboratory measurement of airborne sound insulation of small building elements
ISO 717-1:1996, Acoustics — Rating of sound insulation in buildings and of building elements — Part 1:
Airborne sound insulation
IEC 60942:1991, Sound calibrators
IEC 61043:1993, Instruments for the measurement of sound intensity
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply. The subscripts are defined in
Table 1.
NOTE In this part of ISO 15186, quantities that represent the average over the measurement surface are explicitly
identified using a bar over the measured quantity. For example, I is the average normal intensity over the measurement
n
surface, whereas the quantity, I , without the bar, is the normal intensity obtained at a single point on the measurement
n
surface. This explicit identification of surface average quantities is intended to help the user quickly identify surface
average quantities and to make the nomenclature consistent with the ISO 9614 series. This may make some definitions
appear different from those in ISO 15186-1 and ISO 15186-3 although they are functionally identical.
3.1
average sound pressure level in a source room
L
p1
ten times the logarithm to the base 10 of the ratio of the space and time average of the sound pressure
squared to the square of the reference sound pressure (20 µPa), the space average being taken over the
entire room with the exception of those parts where the direct radiation of a sound source or the near field of
the boundaries (wall, window, etc.) is of significant influence
NOTE 1 This quantity is given in decibels.
NOTE 2 Adapted from the complete definition given in ISO 140-4.
3.2
apparent sound reduction index
R'
ten times the logarithm to the base 10 of the ratio of the sound power incident on the building element under
test to the total sound power radiated into the receiving room by direct transmission and all flanking paths
NOTE 1 Unless special efforts have been made to suppress flanking transmission (i.e. those defined in ISO 140-1), the
measured sound power will contain a flanking component. Annex C provides more details.
NOTE 2 The expression sound transmission loss, which is equivalent to sound reduction index is also in use.
NOTE 3 Adapted from the complete definition given in ISO 140-4.
2 © ISO 2003 — All rights reserved

ISO 15186-2:2003(E)
3.3
sound intensity
G
I
time-averaged rate of flow of sound energy per unit area in the direction of the local particle velocity, in watts
per square metre, which is a vector quantity and is equal to
T
G
1 G
I=⋅pt() u(t) dt (1)
∫
T
where
p(t) is the instantaneous sound pressure at a point, in pascals;
G
ut() is the instantaneous particle velocity at the same point, in metres per second;
T is the averaging time, in seconds.
NOTE This quantity is measured in watts per square metre.
3.4
normal sound intensity
I
n
component of the sound intensity, in watts per square metre, in the direction normal to a measurement
G
surface defined by the unit normal vector n
G
G
I =⋅In (2)
n
G
where n is the unit normal vector directed out of the volume enclosed by the measurement surface
3.5
normal sound intensity level
L
I
n
ten times the logarithm to the base 10 of the ratio of the unsigned value of the normal sound intensity to the
reference intensity I as given by
I
n
L = 10 lg (3)
I
n
I
where
−12
²
I = 10 W/m
3.6
surface pressure-intensity indicator
F
pI
n
difference, in decibels, between the sound pressure level, L , and the normal sound intensity level, L , on
p I
n
the measurement surface, both being time- and surface-averaged, given by
F =−LL (4)
pI
pI
n
n
ISO 15186-2:2003(E)
where
N

0,1L
p
i

LSp = 10 lg 10 dB (5)
∑ M
i

S
M
i=1
and
N
SI
1 Mn
ii
L = 10 lg dB (6)
I
n ∑
SI
M0
i=1
where
L is the time- and surface-averaged sound pressure level measured on the ith sub-area;
p
i
I is the time- and surface-averaged signed normal intensity measured on the ith sub-area, and there
n
i
are N sub-areas having a total area of S
M
N
SS= (7)
MM
∑
i
i=1
NOTE In the limit of equal sub-areas, this indicator corresponds to the negative partial power indicator F defined in
ISO 9614-1 and signed pressure-intensity indicator, F , defined in ISO 9614-3.
pI
n
3.7
pressure-residual intensity index
δ
pI0
difference, in decibels, between the indicated sound pressure level, L , and the indicated sound intensity level,
p
L , when the intensity probe is placed and oriented in a sound field such that the sound intensity is zero
I
δ =−LL (8)
()
pI0 p Iδ
where L is the level of the residual intensity and is given by
Iδ
I
δ
L = 10 lg dB (9)
Iδ
I
NOTE This definition is consistent with that given in the ISO 9614 series. Details for determining δ are given in
pI0
IEC 61043.
3.8
apparent intensity sound reduction index
R'
I
index, in decibels, for a building element that separates one source room and one receiving room, which also
may be the outside, defined as
 
  
S S
M
RL'=− 6+10 lg −L+10 lg (10)
 
  
Ip1 I
n
SS
 
00 
 
where the first term relates to the incident sound power in the source room and the second term relates to the
sound power radiated from the building element(s) contained within the measurement volume in the receiving
room, and
L is the average sound pressure level in the source room;
p1
S is the area of the separating building element under test or, in the case of staggered or stepped
rooms, that part of the area common to both the source and receiving rooms;
4 © ISO 2003 — All rights reserved

ISO 15186-2:2003(E)
L is the average normal sound intensity level over the measurement surface(s) in the receiving room;
I
n
S is the total area of the measurement surface(s);
M
S = 1 m
NOTE 1 Where the intent is to assess the apparent sound reduction index due to all elements radiating sound into the
receiving room, the contribution from this index R' may be combined with the intensity sound reduction index for each
I
flanking element R (see 3.9), as described in Annex C.
I Fj
NOTE 2 The weighted apparent intensity sound reduction index, R' , is calculated according to ISO 717-1 by replacing
Iw
R' with R' .
I
NOTE 3 This index R' differs fundamentally from the apparent sound reduction index R' of ISO 140-4 where total
I
sound power from all receiving sources is measured. The definition of apparent intensity sound reduction index allows
directionality of the intensity probe to be used, to selectively measure the sound power from each receiving room surface
as desired. In principle, by combining the sound power from all surfaces in the receiving room, an estimate of R' can be
obtained; Annex C discusses this in more detail.
3.9
intensity sound reduction index for flanking element j
R
I F j
when a building element separates the source room from the receiving room, this index is defined for a
flanking surface j in the receiving room as
S
 
S
M j
RL=−6+10lg −L +10lg (11)
 Ij 
IjF p1
n

SS
00
 

where the first term relates to the sound power incident on the separating element under test from the source
room and the second term relates to the sound power radiated from the flanking surface j into the receiving
room, and
L is the average sound pressure level in the source room;
p1
S is the area of the separating building element under test or, in the case of staggered or stepped
rooms, that part of the area common to both the source and receiving rooms;
L is the average normal sound intensity level over the measurement surface for the flanking element j
I j
n
in the receiving room;
S is the total area of the measurement surface for the flanking element j in the receiving room;
M j
S = 1 m
NOTE Where the intent is to combine the effect of multiple elements radiating sound into the receiving room, the
contribution from this index can be combined with the apparent intensity sound reduction index, R' for the separating
I
element (see 3.8), as described in Annex C.
3.10
intensity element normalized level difference
D
I ne
difference given by


S
M

DL=−61−L+0lg (12)


Ipne 1 I
 n
A

0

ISO 15186-2:2003(E)
where
L is the average sound pressure level in the source room;
p1
L is the average normal sound intensity level over the measurement surface in the receiving room;
I
n
S is the total area of the measurement surface(s);
M
A = 10 m
NOTE 1 The intensity element normalized level difference is used for small building elements.
NOTE 2 The weighted intensity element normalized level difference, D , is calculated according to ISO 717-1 by
I new
replacing D with D .
ne I ne
3.11
intensity normalized level difference
D
I n
difference given by

S
M

DL=−61−L+0lg (13)

Ipn 1 I
 n
A
0

where
L is the average sound pressure level in the source room;
p1
L is the average normal sound intensity level over the measurement surface in the receiving room;
I
n
S is the total area of the measurement surface(s);
M
A = 10 m
NOTE 1 This index is used when there is not a common building element separating the source room from the
receiving room. Such a situation can occur when the rooms are diagonally separated.
NOTE 2 The weighted intensity normalized level difference, D , is calculated according to ISO 717-1 by replacing D
I nw n
with D .
I n
3.12
modified apparent intensity sound reduction index
R'
I m
index given by
R′′=+RK (14)
II mc
where the values of K are given in Annex A
c
NOTE 1 It is generally recognized that there is a difference between the sound reduction index determined by the
sound intensity method [ISO 15186 (all parts)] and that measured by traditional methods (ISO 140-3, ISO 140-4 and
ISO 140-10) at low frequencies. If the intensity results are to be compared to results measured using the traditional
method, then the intensity results should be adjusted, giving the modified apparent intensity sound reduction index.
NOTE 2 The adaptation values K for in-situ measurements are consistent with K for measurements made in
c c
laboratories (i.e. ISO 15186-1). It is recognized that receiving room conditions may introduce a further bias, as discussed
in Annex B.
6 © ISO 2003 — All rights reserved

ISO 15186-2:2003(E)
NOTE 3 The weighted modified apparent intensity sound reduction index, R' , is calculated according to ISO 717-1
I mw
by replacing R' with R' . Correspondingly the notation for D is obtained.
I m I nemw
3.13
measurement surface
surface totally enclosing the building element under test on the receiving side, scanned or sampled by the
probe during the measurements
3.14
measurement distance
d
M
distance between the measurement surface and the building element under test in a direction normal to the
element
3.15
measurement sub-area
part of the measurement surface being measured with the intensity probe using one continuous scan or that of
a discrete position
3.16
measurement volume
volume bounded by the measurement surface(s), the building element under test, and any adjacent surfaces
that do not radiate significant sound relative to the building element under test
NOTE See 6.4.2.
Table 1 — Subscripts
Subscript Meaning
e element
F flanking
I intensity
i sub-area
j loudspeaker position
m modified
M measurement
p pressure
w weighted
4 Instrumentation
4.1 General
–12 2
The intensity-measuring instrumentation shall be able to measure intensity levels in decibels (ref. 10 W/m )
in one-third-octave bands. The intensity shall be measured in real time when the scanning procedure is used.
The instrument, including the probe, shall comply with class 1 of IEC 61043:1993.
The pressure-residual intensity index, δ , of the microphone probe and analyser shall be adequate to satisfy
pI0
the requirements relative to the surface pressure-intensity indicator F (see 6.5.4) for each measurement
pI
n
sub-area and for the total measurement surface.
ISO 15186-2:2003(E)
NOTE In order to cover the full frequency range different spacers can be required between the probe microphones.
The optimum combination of spacer and frequency band will depend on δ and F . As an example, the following rule
pI
pI0
n
could apply:
 between 50 Hz and 500 Hz, use a 50 mm spacer;
 above 500 Hz, use a 12 mm spacer. The frequency response will normally have to be corrected above 2 000 Hz.
Refer to probe manual for the appropriate method.
Often it is possible to cover the whole frequency range 100 Hz to 5 000 Hz by using a 12 mm spacer and two 12,5 mm
microphones.
The equipment for sound pressure level measurements shall meet the requirements of ISO 140-4. In addition
the microphone in the source room shall give a flat frequency response in a diffuse sound field.
4.2 Calibration
Verify compliance of the sound intensity instrument with IEC 61043 either at least once a year in a laboratory
making calibrations in accordance with appropriate standards, or at least every 2 years if an intensity
calibrator is used before each measurement series.
The following procedure shall be followed before each use of a sound intensity instrument to verify that it is
operating correctly.
a) The instrument shall be allowed to warm up according to the manufacturer’s instructions.
b) Calibrate both microphones for absolute pressure using an IEC 60942:1991, class 1 or better, sound
pressure calibrator.
c) Apply the residual intensity testing device to the two microphones and measure the pressure-residual
intensity index, δ , and ensure that the instrument is within the requirements for its class in the range
pI0
which the residual intensity testing device operates. Phase compensation and any other procedures
recommended by the manufacturer for performance enhancement may be applied. Phase compensation
and pressure-residual intensity testing should preferably be done at a level close to the level of use.
d) If a sound intensity calibrator is available, use this to verify the intensity calibration directly.
5 Test arrangement
5.1 Selecting source and receiving room
In general, the building element under test will be part of a series of building elements separating two rooms.
When choosing which room will be the source room and which will be the receiving room, consideration
should be given to the following facts that can affect the quality of the measurement.
a) Room absorption: a highly absorptive receiving room having a short reverberation time is very beneficial,
while a highly absorptive source room is not.
b) Room volume: the volume of the receiving room is not overly important, while a large source room can
improve the accuracy of the intensity sound reduction index in the low frequencies.
c) Room diffusion: irregular room geometry and randomly located reflecting objects are beneficial in
achieving a uniform sound field in the source room. Such properties are not of significant benefit for the
receiving room.
8 © ISO 2003 — All rights reserved

ISO 15186-2:2003(E)
5.2 Mounting conditions
If the intent is to compare with results from other standards (ISO 140-3 for doors, walls and floors, or
ISO 140-10 for small building elements), the building element under test should meet the requirements of
those standards regarding mounting and boundary conditions.
If the intent is to characterize in-situ performance with the field installation of the actual building element under
test, then no changes to the building element under test shall be made unless explicitly noted in the test report.
6 Test procedure
6.1 General
For each loudspeaker position, measure the average sound pressure level in the source room, L , and the
p1
average sound intensity level on a measurement surface in the receiving room, L . Provided that the
I
n
measurement conditions are satisfactory [i.e. the criterion of Equation (15) is satisfied], calculate the apparent
intensity sound reduction index R' and/or the intensity sound reduction index R for flanking surface(s) j or,
I I Fj
alternatively, the intensity normalized level difference, D
I n.
6.2 Generation of sound field
The sound source, signal and loudspeaker positions shall meet the requirements of ISO 140-4.
6.3 Measurement of average sound pressure level in the source room
Measure the average sound pressure level in the source room according to the procedures given in ISO 140-4.
6.4 Initial test for suitability of the receiving room
6.4.1 Measurement field check
To test the suitability of the receiving room for intensity measurements, switch on the sound source in the
source room and scan with the intensity probe diagonally across the building element under test at a distance
of 0,1 m to 0,3 m (see 6.5.5). The receiving room may be any space meeting the requirements of the field
,
indicator, F (see 4.1 and 6.5.4) and the background noise (see 6.7).
pI
n
6.4.2 Flanking transmission check
Acoustic radiation from building elements adjacent to the measurement surface can adversely affect the
accuracy of the measurements. Building elements that bound the measurement surface should not radiate
significant sound power relative to the building element(s) under test. Annex C provides a method to
determine if these surfaces will have an effect.
6.5 Measurement of average sound intensity level on the receiving side
6.5.1 General
The average sound intensity radiated by the building element shall be estimated for each loudspeaker position
using either the scanning or discrete point method.
6.5.2 Measurement surface
On the receiving side, define a measurement surface that totally encloses the building element under test. For
practicality, the surface may be formed from a number of smaller sub-areas.
ISO 15186-2:2003(E)
If the building element under test is mounted in a niche, the measurement surface is normally the flat surface
of the niche opening. The sound field is usually more uniform in the niche opening than inside the niche. If the
building eleme
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