Tiêu chuẩn iso 11819 2 2017

The close-pro imity CP method spe if ied in the pr sent document has the same main o je tives as the SPB method, but is int en ed t o be used spe ificaly in a plcations that ar compleme

Ac oustics — Measurement ofthe

influenc e ofr oad surfac es on traffic

Part 2:

Aco stique — Méth de de me sura e de l’influence de s r vê tement de 

ch ussée s sur le bruit émis p r la circulation —

Partie 2: Méth de de pro imité immédiate

Fir t edition

2 17-0

Refer ence n mb r

ISO 1 8 9-2:2 17(E)

COPYRIGHT PROTECTED DOCUMENT

© ISO 2017, P blshed in Sw itz rlan

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written permis ion Permis ion c n be req esed from either ISO at the ad r es below or ISO’s member bod y in the c u try of

F reword v

Introduction vi

1 Sc ope 1

2 Nor mati ve r eferenc es 2

3 Terms an definitions 2

3.1 Ro d an pa vement r elated definitions 2

3.2 Measur ement methods an eq ipment 2

3.3 A coustic q antities and symb ls 3

3.4 Symb ls used for correction te ms 4

4 Symbols and abbreviated terms 4

5 Me surement pr inciple 6

6 Me sur ing instruments 6

6.1 Sou d level instrumentation 6

6.2 Fr eq ency analysis ins rumentation 7

6.3 Sou d calbr ation instrumentation 7

6.4 Vehicle spe d measuring ins rumentation 7

6.5 Position monitoring ins rumentation 7

6.6 Temperatur e measuring instrumentation 7

6.7 T yr e lo d measuring eq ipment 7

6.8 Inflation pr es ure measuring eq ipment 7

6.9 Ve ification of measuring sys em an measuring ins rumentation 7

7 Test sites 8

8 Meteor olog ical c onditions 8

8.1 Win 8

8.2 Temperatur e and othe weathe -related is ues .8

9 Test vehicle 9

9.1 General desig n 9

9.2 Micr ophone p sitions and mou ting 9

9.3 Pe formanc r eq ir ements an conformity of thetes vehicle 1

9.4 Referenc tyr es 1

9.5 T yr e rub e hardnes 1

9.6 T yr e mou ting 1

9.7 T yr e ru -in 1

10 Me surement proc ed r e 12

1 1 Pr eparations for measur ement 1

1 2 Measur ement of sou d 1

1 3 Pr oc dure for s ud y of typical r oad se tion 1

1 4 Minimum numbe of ru sfor ve y short r oad se tions 1

1 5 L teral position on the r oad 1

1 6 L ng itudinal p sition on the r oad 1

1 7 Consideration of distur bing noise 1

1 8 Tes vehicle spe d 1

1 8.1 Referenc spe ds 1

1 8.2 Tes spe d an ac eptable deviations 1

1 9 T yr e lo ds 14

1 1 T yr e inflation 14

1 1 Temperatur e measur ement 14

1 1 1 General 14

1 1 2 A ir temperatur e 1

1 1 3 Ro d surfac temper atur e (o tional) 1

1 1 Ove view and summary 1

11 A nal ysis proc edure 15

1 1 Definition of s eps in the calculation pr oc s 1

1 2 Result ex pr es ed as o er al levels 1

1 2.1 General 1

1 2.2 C se A 1

1 2.3 C se B .1

1 2.4 Ex r es ion of CP levels 1

1 3 Result ex pr es ed as one-thir d-octa ve-b n levels 1

1 3.1 General 1

1 3.2 C se A 1

1 3.3 C se B .1

1 4 Correction for analysis of spe tral levels 1

1 5 Acoustic v ria i ty 1

12 Me surement u c er tainty as es ment ac c ordin to ISO/IEC Guide 98-3 .19

13 Repe tabiity and reprod cibiity: System c ompar ison ac c or ding to ISO 5 25-2 21 14 Test rep rt 21 A nne x A (normative) Cer tificatio of the test vehicle .24 A nne x B (normative) Averag ing within e ch road seg ment 30 A nne x C (informative) Detaied ex planation of the calculation pr oc edure 32 A nne x D (informative) A ppl cabiity of ISO 1 819 meth ds .37 A nne x E (informative) Guidelnes for desig n and use of the test vehicle 39 A nne x F (informative) Guidelnes for me sur ements 43

A nne x G (informative) A ppl cation of the CPX metho for sur veying lar g e road networ ks 45

A nne x H (informative)A pplcatio of the CPX metho for other objecti ves 48

A nne x I (informative)Summary of me sur ement parameter s 49

A nne x J (informative) Val dity and stabi ity of the method 50

A nne x K (informative) Me surement unc er tainty 53

A nne x L (informative) Referenc e road surfac e

56 A nne x M (informative)Calculation of close-pr ox imity so nd indic es 58

A nne x N (informative) Summar y of me suring and data-pr oc es ing pr oc edur es 59

A nne x O (informative) Example of test repor t 61

Biblog raph y 64

ISO (he Int ernational Org nization for Stan ardization) is a worldwide fede ation of national s an ards

b dies (ISO membe b dies) The work of pr p ring Int ernational Standards is normaly car ied out

through ISO t ech ical committ ees Each membe b dy int er st ed in a subje t for w hich a t ech ical

committ ee has be n es a l shed has the right t o be r pr sent ed on that committ ee Int ernational

org nizations, g ove nmental an non-g ove nmental, in laison with ISO, also take part in the work

ISO cola orat es closely with the Int ernational Ele trot ech ical C mmis ion (IEC) on al matt ers of

ele trot ech ical s an ardization

The proc d r s used t o develo this document an those int en ed for it furthe maint enanc ar

desc ibed in the ISO/IEC Dir ctives, Part 1 In p rticular the dife ent a pro al c it eria ne ded for the

dife ent ty es of ISO document should be not ed This document was draft ed in ac ordanc with the

edit orial rules of the ISO/IEC Dir ctives, Part 2 ( e www iso org dir ctives)

A tt ention is drawn t o the p s ibi ity that some of the element of this document ma be the subje t of

p t ent right ISO shal not be held r sponsible for identifying any or al such p t ent right Detais of

any p t ent right identified d ring the develo ment of the document wi be in the Introd ction an / r

on the ISO ls of p t ent de larations r c ived ( e www iso org p t ent )

Any trade name used in this document is information given for the convenienc of use s an does not

cons itut e an en orsement

F or an ex lanation on the v lu tary natur of s an ards, the meaning of ISO spe if ic t erms an

ex r s ions r lat ed t o conformity as es ment, as wel as information a out ISO’ s adhe enc t o the

World Trade Org nization (WTO) principles in the Te hnical Bar ie s t o Trade (TBT) se the folowing

URL: www iso org iso / for word html

This document was pr p r d b Te h ical Committ ee ISO/TC 43, Ac ous tic s , Subcommitt ee SC 1, Noi se

A l s of al p rt in the ISO 1 8 9 se ies can be fou d on the ISO websit e

The emis ion an pro a ation of ro d traffic noise gr atly depen s on ro d surfac charact eris ics,

nota ly on t extur , flow r sis ivity an acous ic a sorption Al these charact eris ics influenc the

gene ation of tyre/ ro d noise an , in ad ition, the acous ic a sorption can influenc the pro a ation

of soun , p rticular ly w hen the pro a ation takes plac close to the surfac Powe u it noise, w hich is

usualy gene at ed at a gr ater height a o e the ro d surfac than tyre/ ro d noise, ma also be afe t ed

d ring pro a ation b the p rosity charact eris ics of the ro d surfac These efe t lead t o dife enc s in

sou d pr s ur levels, as ociat ed with a given traffic flow an comp sition, from dife ent ro d surfac s

of up t o 1 d , w hich can ha e a subs antial imp ct on the environmental q alty alongside a ro d

It is the efor important t o be a le t o measur the influenc of surfac charact eris ics on tyre /ro d noise

b a s andardiz d method W ithin the cons raint of this method, this document ofe s an o je tive

rating of the ro d charact eris ics t o satis y a ne d ex r s ed b ro d plan e s, ro d adminis rat ors,

contract ors, man factur rs of so-caled “low-noise surfac s” and othe p rties conc rned with the

control of ro d traff ic noise

A method satis ying the ne ds ex r s ed in the for g oing, but ha ing se ious practical cons raint ,

a pears in ISO 1 8 9-1 That method, caled the s atis ical p s -b ( SP ) method, is int en ed for

use es ential y for two main purp ses It can be used: firs , t o clas ify surfac s in ty ical an g ood

con ition as a ty e ac ording t o their influenc on traffic noise ( urfac clas if ication); an se on , t o

ev luat e the influenc on traffic noise of dife ent surfac s at p rticular sit es ir espe tive of con ition

an ag e Howeve , d e t o seve e r q ir ment on the acous ical environment at the measur ment it e,

the method can ot g ene aly be used for a pro al of new or r bui t surfac s at any arbitrary location

In ad ition, the SP method has a n mbe of othe practical lmitations, w hich ar outlned in An ex D

The method spe if ied in this document, t og ethe with ISO/TS 1 8 9-3, complement the SP method in

a plcations w he e the latt er has l mitations

Ac oustics — Measurement ofthe influenc e ofr oad surfac es

Part 2:

This document spe if ies a method of ev luating dife ent ro d surfac s with r spe t t o their influenc

on traff ic noise, u de con itions w hen tyre / ro d noise dominat es The int erpr tation of the r sult

a ples t o fr e-flowing traffic tra el ing on es entialy level ro ds at cons ant spe ds of 40 km/h an

upwards, in w hich cases tyre / ro d noise is as umed t o dominat e (although in some countries it is

p s ible that tyre / ro d noise does not dominat e at 40 km/h w hen the pro ortion of hea y vehicles is

high) F or othe driving conditions w he e traffic is not fr e-flowing, such as at ju ctions or un e hea y

ac ele ation, an w he e the traffic is cong est ed, the influenc of the ro d surfac on noise emis ion is

mor complex This is also the case for ro ds with high longitu inal gradient an a high pro ortion of

hea y vehicles

A s andard method for comparing noise charact eris ics of ro d surfac s gives ro d an environment

authoritiesa t ool for es a l shing common practic s or l mit as t o the use of surfacings me ting c rtain

noise c it eria Howeve , it is not within the sco e of this document t o sugg es such c it eria

ISO 1 8 9-1 def ines anothe method: the s atis ical p s -b ( SP ) method The close-pro imity (CP )

method spe if ied in the pr sent document has the same main o je tives as the SPB method, but is

int en ed t o be used spe ificaly in a plcations that ar complementary t o it, such as:

— noise charact erization of ro d surfac s at almos any arbitrary sit e, with the main purp se of

che king compl anc with a surfac spe ification (an ex mple for conformity of prod ction is

sugg est ed in R efe enc [1]);

— che king the acous ic efe t of maint enanc an con ition, e.g wear ofan damag e t o surfac s, as

wel as clo ging an the efe t of cleaning of p roussurfac s;

— che king the longitu inal an lat eral homog eneity of a ro d se tion;

— thedevelo ment of q iet er ro d surfac s an r sear h on tyre /ro d int eraction

NOTE T is document do s not des rib the con itions of ap lication for formal p rposes of the me surement

with the C X method Such con itions may b def ined in other stan ards or le al t exts However, sug estions for

the ap lica ility of ISO 1 8 9-1 an this document are provided in An e D

Measur ment with the CP method ar fast er an mor practical than with the SP method, but ar

mor lmit ed in the sense that it is r lev nt only in cases w he e tyre / ro d noise dominat es an powe

unit noise can be negle t ed Furthe mor , it cannot take hea y vehicle tyre /ro d noise int o ac ou t as

ful y as the SP method can, sinc it uses a lght truck tyr as a pro y for hea y vehicle tyr s an does

not ake powe u it noise int o ac ou t

The CPX method spe if ied in this document is int en ed t o measur the pro e ties of ro d surfac s,

not the pro e ties of tyr s If the method is used for r sear h purp ses, t o pro ide an in ication of

dife enc s betwe n tyr s, the lo ds an inflations would normaly be adjust ed t o othe v lues than

spe if ied in this document

2 Normati ve referenc es

The folowing document ar r fe r d t o in the t ext in such a wa that some or al of their cont ent

cons itut es r q ir ment of this document F or dat ed r fe enc s, only the edition cit ed a ples F or

un at ed r fe enc s, the lat es edition of the r fe enc d document ( inclu ing any amendment ) a ples

ISO 5 2 - 2, Acc uracy (truenes s a d pr c i s ion ) o meas ur ment meth ds a d r s ults — Part 2 : B as ic meth d

fr the dete min tio o r peata i t y a d r produc ibi t y o a s ta dard meas ur ment meth d

ISO 1 8 9-1, Ac ous tic s  —  Meas ur ment  o  the  influenc e  o  ro d  s urfc es  o   tra fic   n i s e  —  Part  1: 

Stati s tic al Pas s-By meth d

ISO/TS 1 8 9-3, Ac ous tic s — Meas ur ment  o the  influenc e  o  ro d  s urfc es  o   trafic  n i s e  —  Part  3 : 

R efe enc e t yres

ISO/TS 1 47 -1, Ac ous tic s — Tempe atur  influenc e o  t y re/ro d n i s e meas ur ment — Part 1: Cor ec tio  

fr tempe atur  when tes tin  w ith the CPX meth d

IEC 6 942, Elec tro c ous tic s — S u d c albrators

IEC 612 0-1, Elec tro c ous tic s — Oc ta e -b nd a d frac tio aloc ta e -b nd fite s — Part 1: S ec ific atio s

IEC 616 2-1, Elec tro c ous tic s — S u d level mete s — Part 1: S ec ific atio s

ISO/IEC G ide 9 -3, Unc ertaint y  o  meas ur ment  —  Part  3:  Guide  to  the  ex pr s s io   o  u c ertaint y  in 

meas ur ment (GUM: 19 9 5)

3 Terms and definitions

For the purp ses of this document, the terms an definitions given in ISO 1 8 9-1 an the folowing a pply

ISO an IEC maintain t erminolo ical data ases for use in s an ardization at the folowing ad r s es:

— IECEle tro edia: a aia le at ht p:/ www ele tro edia org

— ISO Onlne brow sing plat orm:a ai a le at ht p:/ www iso org o p

3.1 Road and pavement related definitions

3.1.1

road sectio

t otal s r t ch of the ro d lane subje t t o t es ing

3.1.2

road se ment

p rt of a ro d se tion, being 2 m long an int en ed for normal zation of sou d pr s ur levels from the

actual spe d on that segment t o a c rtain r fe enc spe d

3.2 Measurement methods and equipment

3.2.1

statistical pas -b meth d

SPB metho

measur ment proc d r designed t o ev luat e vehicle an traffic noise g ene at ed on dife ent se tions

of ro d surfac un e spe if ic traff ic con itions

Not e 1 t o entry: The me surements are taken from a gre t n mb r of vehicles operating normaly on the ro d

R esults o tained using this proced re are normalized to stan ard spe ds ac ording t o the cate ory or ty e of

ro d b ing considered T e method is specif ied in ISO 1 8 9-1

reference tyres

t es tyr s spe if ied for the purp se of r pr senting c rtain featur s in tyre / ro d soun emis ion,

designed an cons ruct ed for use in this method with spe if ied an r prod cible s an ard pro e ties

Note 1t o entry: T e reference tyres are specif ied in ISO/TS 1 8 9-3

3.3 Ac oustic quantities and symbols

time-a e ag ed A-weight ed soun pr s ur level ( SPL) of the tyre /ro d noise as det ermined b the CP

method, eithe bro db n or spe tral b n s, as r q ir d

Note 1 to entry: T e C X level is e pres ed in decib ls In order t o provide more information,ad itional suff ix es

A-weight ed soun pr s ur level charact erizing the ro d surfac un e t es , w hich is b sed on the

tyre /ro d soun pr s ur levels of one or mor tyr sr pr sentative of p s eng er car tyr s

A-weight ed soun pr s ur level charact erizing the ro d surfac un e t es , w hich is b sed on the

tyre /ro d soun pr s ur levels of one or mor tyr sr pr sentative of hea y vehicle tyr s

Note 1 to entry: The L

C X:I

is e pres ed in decib ls The method is inten ed to des rib performance of ro d

surfaces for a certain traff ic composition in a similar way t o the SP method in ISO 1 8 9-1, although the

n merical values for a given spe d are higher More information on the calculation of C X in ices is given in

s an ard deviation of the A-weighted sou d pr s ur levels o e al segment , when using r fe enc tyr t

Note 1 t o entry: T e acoustic varia ility is e pres ed in decib ls This varia ility is normaly dominated by

ro d surface variations, although ran om u certainties could ad a lit le.Me surement spe d an whe l tracks

normaly do not influence this value signif icantly T is me sure is, therefore, considered t o b an in ication of

ro d surface homo eneity as far as noise properties are concerned

3.4 Symbols used for corr ection ter ms

3.4.1

me sured spe d

ν

actual spe d d ring a measur ment

Not e 1t o entry: T e me sured spe d is e pres ed in kilometres per hour

3.4.2

reference spe d

v

ref

pr fe r d spe d for measur ment

Not e 1 t o entry: T e reference spe d is e pres ed in kilometres per hour Most commonly used reference spe ds

are 5 km/h, 8 km/h an 1 0 km/h, but alternative spe ds may b used if req ired for tech ical, safety or

le islative re sons

3.4.3

spe d coef icient

B

coefficient det ermining the spe d depen enc of the sou d pr s ur levels, normal y used for cor e tion

of the sou d pr s ur level t o a c rtain r fe enc spe d

Not e 1 to entry: T e cor ection for deviations from the reference spe d is given by the e pres ion B ⋅lg(v v

r f,

e pres ed in decib ls, where B is dimensionles Values of B for specif ic pavements are given in 1 1 d)

3.4.4

temperature coef icient

γ

t

coefficient used for cor e ting CP level for the efe t of t empe atur for tyr t

Not e 1t o entry: T e temperature co ff icient is e pres ed in decib ls per de re Celcius

3.4.5

rubbe hardnes coef icient

β

t

coefficient used for cor e ting CP level for the efe t of tr ad rub e hard es of tyr t

Not e 1 to entry: T e rub er hard es co ff icient is e pres ed in decib ls per Shore A R efer t o 1 1 f) for

cor e tion for in ivid al measuring devic s in one-third-octa e b n s from 3 5 Hz t o 5 0 0 Hz with

the c ntr fr q ency f, t o ac ou t for deviations from acous ic hemi-fr e-f ield con itions

Not e 1 to entry: The device cor ection for sou d reflections is e pres ed in decib ls Information on the

determination of C

d,f

is given in A.2

4 Symbols and abbr eviated terms

Ta le 1 ls s the symb ls used in this document Al acous ic v ria les ar A-weight ed

Table 1 — Symbols and abbreviated terms used in this document an their value or unit

Me sure of the acoustic properties of the tested

ro d section, for tyre t, at the reference spe d v

E ergy-b sed avera e spectrum at he mic op one

positions m = 1 an m = 2(for the subs ript

d

Time-avera ed tyre /ro d SP (“CPX level”) over the

time it akes t o ru a ro d se ment (2 m)

Me sure of the acoustic properties of the test ed ro d

section, for tyre(s)“ P” representing pas eng er ar

an other light vehicles, at the reference spe d, v

Me sure of the acoustic properties of the tested

ro d section, for tyre(s) “H” representing he v

vehicles, at he reference spe d, v

“CPX in e ” representing the overal acoustic

properties of the tested ro d section,for tyre(s)

representing light an he v vehicles combined

(with eq al weighting), at the reference spe d, v

r f

Spe d co ff icient; i.e inc e se in C X level with

t enfold inc e se in spe d, to b a le to cor ect or

deviations from the reference spe d, v

r f

C

d,f

d

Device cor ection term (freq ency depen ent) to

ac ou t or deviations from fre f ield con itions

γ

t

d /°C

Temperature co ff icient for cor ection for tyre t t o

ac ou t or deviations from reference temperature

of 2 °C T e value is ne ative for tyres P1 an H1

β

t

d / hore A

R ub er hard es co ff icient for cor ection for

tyre t t o ac ou t for deviations from a reference

Front an re r man atory mic op one positions

Optional mic op one positions

Total n mb r of ru s, n

r, whe l tracks, n

w, or ro d

T re ty e def ined for testing

Pas eng r car tyres

He v vehicle tyres or ap ro imat e pro y

T

i

°C

Air temperature at ro d se ment i (in e not

ne ded if contin ous temperature me surements

are not made)

Symb l Value/u it E planation

v

r f

km/h

Prefer ed nominal spe d for me surement; th s a

reference spe d used when reporting results

T e whe l tracks in a lane where test yres are

rol ing Track n mb r 1 is closest o the ro d

shoulder, 2 is the op osite whe l track within that

same lane; 3, 4, an so on are ad itional tracks

In the CPX method, the a e ag e A-weight ed SPLs emitt ed b spe if ied tyr s ar measur d o e

an arbitrary or a spe ified ro d dis anc , t og ethe with the vehicle t es ing spe d, b at leas two

mic o hones locat ed close t o the tyr s F or this purp se, a spe ial t es vehicle, w hich is eithe self

-p we ed or t owed behin anothe vehicle, is used R efe enc tyr s ar mount ed on the t es vehicle,

eithe one b one or b th at hesame time Two uniq ely dife ent r fe enc tyr s ha e be n sele t ed in

orde t o r pr sent the tyre /ro d charact eris ics w hich ar t o be s u ied

Although the mic o hones ar p sitioned in close pro imity t o the sour e of tyre / ro d noise, a

subs antial p rt of the pro a ation efe t as ociat ed with acous ical y a sorptive surfac s is actualy

inclu ed in the mic o hone signal This is demons rat ed b model calculations an the r sult ofthe

CP v ldation ex e iment (R efe enc s [2], [3]) S e An ex D for furthe information

The t es s ar pe formed with the int ention of det ermining a tyre / ro d soun pr s ur level, he e

r fe r d t o as the CP level, L

C X, at one or mor of the nominat ed r fe enc spe ds This can be

achieved b t es ing at a r fe enc spe d or b normal zing for spe d deviations

F or each r fe enc tyr an each in ivid al t es ru with that tyr , the a e ag e soun pr s ur

levels o e short measuring dis anc s ( egment of 2 m each), t og ethe with the cor esp n ing

vehicle spe ds, ar r corded The soun pr s ur level of each segment is normalz d t o a r fe enc

spe d b a simple cor e tion proc d r Ave a ing is then car ied out ac ording t o the purp se of the

measur ment, i.e measuring a p rticular segment or a n mbe of conse utive segment (a se tion)

The CPX level, L

v

C X:t

r ef,, is the r sulting a e ag e sou d pr s ur level for the two man at ory

mic o hones at the r fe enc spe d, v

reffor r fe enc tyr t, w he e t is P or H

Whe e b th close-pro imity sou d levels have be n det ermined, the close-pro imity sou d in ex L

C X:I

is the a e ag e of L

C X:Pand L

C X:Hwith eq al weight given t o the two in ic s L

C X:I

is int en ed for

single v lue comp rison

The e ar some is ues in the method w hich dese ve spe ial ca ution w hen a plying this method, espe ialy

un e cir ums anc s that ar not the mos common Annex J pro ides a discus ion ofsuch is ues

6 Measuring instruments

6.1 S und level instrumentation

W ithin the minimum fr q ency rang e of 3 5 Hz t o 5 0 0 Hz, the soun level met er or the eq iv lent

measuring sy st em shal me t the r q ir ment of IEC 6 16 2-1, clas 1 The mic o hones shal be of the

“ r e-field” ty e

An a pro riat e win sc e n shal be used ha ing a diamet er of at leas 9 mm The sou d pro e ties

of windsc e ns wi l det eriorat e as the mat erial is pro r s ively ex osed t o dirt It is the efor g ood

practic t o che k the pe formanc of the win sc e ns fr q ently an t o r plac them with new, fr sh

mat erial w hen they show p tt erns of dirt co e ag e

Table 1 (c ontin ed)

6.2 F r equency anal ysis instr umentation

Fr q ency analy sis of the measur d soun using one-third-octa e-b n r solution is man at ory The

rang e 3 5 Hz t o 5 00 Hz (c ntr fr q encies of one-third-octave ban s) is the minimum rang e t o be

co e ed The one-third-octa e-b n f ilt ers shal conform t o IEC 612 0-1

6.3 S und cal bration instrumentation

A t the beginning of the measur ment , an folowing any warm-up time spe if ied b theman factur r,

the o e al sensitivity of the sou d level met ers or the eq iv lent measuring sy st em ( inclu ing the

mic o hone) shal be che ked If ne es ary, adjus it ac ording t o the man factur r’ s ins ructions This

ma r q ir use of a s an ard sou d sour e, such as a calbrat or or pist onphone This che k shal be

r peat ed at he en of the measur ment , an at leas aft er eve y 4 h of o e ation Any deviations shal

be r corded in the t es r p rt If the calbration r adings dife b mor than 0,5 d between the che ks,

al int ermediat e measur ment shal be conside ed inv ld

The sou d calbration devic shal me t the r q ir ment of IEC60 42, clas 1

6.4 Vehicle speed measur ing instrumentation

The a e ag e spe d of the vehicle o e the measur d segment shal be measur d, with a ma imum

pe mis ible e ror of ± % of the in icat ed v lue

F or spe d measur ment, if a tyr is used it hal not be mou t ed on a drive a le

6.5 P osition monitoring instrumentation

GPS or othe means of identifying the s art p sitionsof measur ment ar ve y useful in orde t o avoid

pro lems in identifying a t es se tion an t o be a le t o r turn t o the same plac at a lat er oc asion or

for othe ty es of measur ment It is r commended that the GPS sy st em is of a ty e spe ified with a

ma imum pe mis ible e ror of ± m

6.6 Temperature measuring instr umentation

The air an (o tional) ro d t empe atur measuring ins rument (s) shal ha e a ma imum pe mis ible

e ror of ± °C, as spe if ied b the man factur r Met ers uti izing the infrar d t echniq e shal not be

used for air t empe atur measur ment

6.7 T yre load measuring equipment

The weighing eq ipment used t o det ermine the lo d of the t es tyr s shal ha e a ma imum pe mis ible

e ror of ± %, as spe if ied b the man factur r

6.8 Inflation pres ure measur ing equipment

The eq ipment used t o det ermine the inflation pr s ur of the t es tyr s shal ha e a ma imum

pe mis ible e ror of ±4 %

6.9 Verification of measuring system and measur ing instrumentation

The compl anc of the soun calbrat or with the r q ir ment of the a pro riat e clas of IEC 6 942

shal be ve if ied ann al y The complanc of the sou d level met er or eq iv lent measuring sy st em

with the r q ir ment of IEC6 16 2-1 shal be ve ified at leas eve y two years Thisshal be pe formed

b a la orat ory authoriz d t o pe form calbrations trac a le t o the a pro riat e s an ards It is

r commen ed that al othe ins rumentation should be calbrat ed at leas eve y two years

7 Test sites

In pe forming a CP measur ment, the e ar a n mbe of practical cons raint w hich def ine the

minimum r q ir ment for the ro d se tion t o be suita le for as es ment These can be summariz d as

folows

— The a pro ch t o the ro d se tion shal be of sufficient length t o alow the r fe enc spe d t o be

r ached befor r aching the ro d se tion The e shal be a ru -in of at leas 1 m of the same surfac

ty e befor the ro d se tion begins

— The ro d se tion (ex clu ing the run-in) shal be at leas 2 m long, an pr fe a ly long er than 1 0 m

— The ro d se tion shal not inclu e ben s with a radius of curv tur les than 2 0m at 5 km/h an

5 0 m at 8 km/h

— The surfac of the ro d se tion up t o a dis anc of 0,5 m pe pen icularly from the sidewal of the

t es tyr facing the mic o hone shal be the same surfac ty e as in the w he l track or ha e simiar

acous ical impedanc charact eris ics

— The l mitations on backgroun noise at the t es sit e ac ording t o A.5 shal be o se ved

— Whe e measur ment ar taken using a t es vehicle without an enclosur ( e 9.1), those p rt of

thero d se tion w he ethe ear r fle ting surfac s within a dis anc of 2 m from the mic o hone

shal be ex clu ed from the as es ment This inclu es guard rai s, Je sey b r ie s or any othe

b r ie s or emb nkment , rocks, parked vehicles, bridg es an buidings In cases w he e the t es

vehicle inclu esan enclosur complying with ther q ir ment of An ex A, no r s rictions a ply t o

o je t at thero dside

W ith r g rd t o the las r q ir ment, 2 m is sele t ed as a pr caution a ains the p s ible efe t of

multiple r fle tions between two hard surfac s: the vehicle side p nel ( if any) an the ro dside o je t

If the use can show that such r fle tions for the vehicle con guration o p sit e a sold p ralel wal

neve have any influenc on the measur d levels at a dis anc les than 2 m, the dis anc can be r d c d

t o that lowe dis anc – howeve , neve les than 1 m If a plca le for the t est ed ro d, such r fle tion

t es s shal be r fe r d t o in the t es r port

8 Meteorolog ical conditions

It isr commen ed that ambient win spe d does not ex ce d 5 m/s at the mic o hone height d ring the

measur ment for t es vehicles without an enclosur arou d the mic o hone an t es tyr If the t es

tyr () is /ar enclosed, win spe ds up t o 1 m/s ar ac epta le

If the t es vehicle man factur r or use can pro e that the vehicle can tra el in highe win spe ds, in

any dir ction, without a significant influenc on the measur ment r sult, the r commen ation a ove

can be ignor d The same con itions as in A.3.2 shal then be met

8.2 Temperatur e and other we ther -related is ues

Measur ment shal be car ied out only w hen ro d surfac s ar dry an ambient air t empe atur is

within the rang e r pr sentative for that clmatic zone:

— mode at e an continental: 5 °C t o 3 °C;

— tro ical an subtro ical:1 °C t o 3 °C

The surfac s can be as umed t o be suff iciently dry if the minimum time pe iods for drying -up aft er

rainfal given in Ta le F.1 ar o se ved

NOTE 1 T e alowed temperature rang is related to local ro d materials In the warmer zones, high

temperatures are common an bitumen vis osity is adjusted t o it, while the same t emperature in a co ler climate

can cause ble ding of the bitumen T is is k own t o cause e tra stick-snap sou d from the rol ing tyre

NOTE 2 An e F also gives guidelines for estimating the level of moisture within the voids of porous surfaces

by a simple test method

9 Test vehicle

9.1 General desig n

The t es vehicle ma be one of thefolowing ty es

— A self-p we ed vehicle on w hich one or two r fe enc (t es ) tyr () is/ r fitt ed t o the a le closes

t o the mic o hones It could also be a vehicle with an extra tyr f itt ed for t es ing purp ses

— A traie t owed b a sep rat e vehicle The e shal be one or mor t es tyr s, w hich ar mou t ed on

thetraie Ad itionaly, the traie ma ha e tyr s for sup ort

The t es tyr ( ) ma or ma not be sur oun ed b an enclosur co e ing the tyr s ex cept for a c rtain

clearanc t o the ro d, the purp se of w hich is t o prot ect he mic o hones from ext ernal noisean win

influenc s

The r q ir ment on the t es vehicle ha e the o je tive t o come as close as p s ible t o the r fe enc

case in w hich a tyr is rol ng on a ro d surfac with mic o hones in an acous ical hemi-fr e-field, i.e

w he e the e ar no sou d r fle tions ex cept from the ro d surfac an no b ckgroun noise

The r q ir ment an design r commen ations in the folowing ar int en ed t o a pro ch this ideal

situation within practical cons raint

F or the purp ses of this document the e ar thr e sour es of u want ed contribution t o the fr e f ield

sou d transmis ion from tyr t o mic o hone:

a) backgroun noise r lat ed t o the sy st em, consis ing of sour es such as win noise an sou d from

thet owing vehicle;

b) backgroun noise from u r lat ed sour es such as p s ing vehicles an r fle tions a ains ro dside

o je t ;

c) contributions from unwant ed r fle tions a ains p rt of the sy st em, such as insufficiently

a sorbing enclosur s an part of suspensions sy st ems

The vehicle shal comply with the r q ir ment desc ibed in An ex A S e also 1 7 r g rding

p s ibi ities of discarding segment w he e this r q ir ment is ex ce ded

9.2 Microphone positions and mounting

A t leas two mic o hones shal be used The two man at ory mic o hones shal be in o e ation

simultaneously The p sitions of the man at ory mic o hones u de s atic condition r lative t o the t es

tyr shal be as folows ( e Figur 1and Ta le2):

— dis anc horizontaly from the plane of an u defle t ed part of the tyr sidewal shal be 0,2 m

±0,0 m;

— theheight a o e p vement level shal be 0,1 m ± 0,0 m

Al measur ment r fe t o the c ntr of the mic o hone dia hra m It is r commen ed that he “ ront

mic o hone (1) be turned at an angle of 45° t o the rol ing dir ction, an the “ rear“ mic o hone (2) be

turned at an angle of 1 5° t o the rol ng dir ction, as shown in Figur 1 Howeve , in the case of

non-enclosed sy st ems, it ma be pr fe a le t o mou t the mic o hones p ralel t o the driving dir ction in

orde t o r d c p t ential influenc of air turbulenc

Optional p sitions at angles of 0 9 ° , an 1 0° t o the rol ing dir ction as in icat ed in Figur 1 ma

be used in cases w he e the use want a mor complet e ma ping of the tyre /ro d noise dir ctional

pro e ties

Figur 1 shows the mic o hones on the lef side of the t es w he l as embly Depen ing on the

cons ruction ofthe t es vehicle, the mic o hones ma also be mou t ed on the right han side, but

mic o hones 1 an 4 shal then r main at the front p sition

When mou ting the mic o hones it is important t o make sur that he mounting is ro us in orde that

vibrations in the mic o hones do not afe t the measur ment It has be n r p rt ed in lt eratur that

vibrations ma afe t he measur d noise levels

[1 ]

NOTE If using r fe enc tyr s of subs antial y dife ent dimensions than that of P1 an H1 (as

spe ified in ISO/TS 1 8 9-3), one mus be awar that the soun levels in mic o hones 4 t o 6 wi l be

highly influenc d b the dis anc (d

3

an d

4) betwe n the mic o hones and the trai ing an leading

edg es of the tyre / ro d contact pat ch In case of tyr comparisons, it could then be mor r lev nt t o

ke p the dis anc betwe n the mic o hones an the contact edg es cons ant

Figure 1 — Mic op o e positions for the me surements

Table 2 — The mic o hone positio s in Figure 1

9.3 P erformanc e requirements and c onformity ofthe test vehicle

The t es vehicle an measur ment sy st em pe formanc shal comply with the r q ir ment in Annex A

A dditional che ks on t es vehicle pe formanc r lat ed t o b ckgroun noise (A.3) shal bemade prior t o

t es ing u de the folowing cir ums anc s

— If the tyr s on eithe the t es vehicle ( if self-powe ed) or the t owing vehicle ar in significantly

dife ent con ition t o w hen the t es vehicle was las c rtif ied This is of p rticular imp rtanc on

t es vehicles w hich do not inclu e any form ofenclosur arou d the t es tyr

— If the t owing vehicle is of a signif icantly dife ent ty e t o that used w hen the t es vehicle was las

c rtif ied

9.4 Referenc e tyres

R efe enc tyr s ar t es tyr s spe if ied for the purp se of r pr senting c rtain featur s in tyre / ro d

sou d emis ion, sele t ed for use in this method with spe ified an r prod cible s an ard pro e ties

The s an ard r fe enc tyr s shal be P1 an H1 as spe if ied in ISO/TS 1 8 9-3 Depen ing on the

purp se of the measur ment, one or b th ar used

Tyr s othe than P1 an H1 ma be used for r sear h or spe ial survey purp ses A desc iption of the

alt ernative tyr s shal then be inclu ed in the t es r p rt

NOTE T e ad anta es of using reference tyres in comparison t o using some mix of market tyres is that it

ensures consistency an availa ility of the t est tyres over time an international compara ility of me surement

results

It is r co niz d that w hen this s andard is implement ed in in ivid al cou tries, the e could be a ne d

t o use r fe enc tyr sothe than P1an H1in orde t o r pr sent local con itions or t o ad r s fitment

p s ibi ities on a aia le CPX sy st ems This is ac epta le, but the alt ernative r fe enc tyr s as wel

as the jus ification for their use should be set out in the r lev nt national implementation guidel ne or

sy st em C nve sion of L

C X

v lues for the alt ernative r fe enc tyr s t o those v lues eq iv lent t o P1

an H1 is useful only for in icative comp risons

9.5 T yre rubber har dnes

The rub e hardnes of the t es tyr s shal be measur d at leas every thr e months R efe t o

ISO/TS 1 8 9-3 for the t es ing proc d r

9.6 T yre mounting

The t es tyr s shal be mount ed on the t es vehicle such that

— any in icat ed rotational dir ction is r spe t ed, or

— any “out ide” marking is r spe t ed, or

— the sidewal with the ful DOT mark ( inclu ing the prod ction we k /year n mbe ) fac s the

mic o hones

Onc a tyr mou ting has be n sele t ed, tyr s shal be mount ed in this wa throughout their use as

r fe enc tyr s for this purpose

9.7 T yr e r un- n

Tyr ru -in is imp rtant and is desc ibed in ISO/TS 1 8 9-3

10 Measurement proc edure

10.1 Preparations for measurements

The mic o hone p sition shal be che ked r gularly, e.g each time a t es tyr is chang ed or w hen an

acous ical calbration is made Whe e a self-p wer d t es vehicle is used one shal che k the mic o hone

p sitions at ty ical o e ating con itions, i.e with drive and p s ible o e at ors onb ard an with

ty ical amou t of fuel in the tank, et c

Befor any s an ard measur ment takes plac the tyr s shal be brought t o normal o e ating

t empe atur Methods for achieving this inclu e driving the t es vehicle for at leas 1 min for warm-up

r pr sentative of r fe enc spe ds up t o 8 km/h and at leas 1 min at the highe r fe enc spe ds

The t es tyr s shal be ex mined r gularly for damag e t o the tr ad an for the pr senc of for ign

o je t in the tr ad Chip ings or othe dirt in the tr ad shal be r mo ed befor t es ing takes plac an

w he e a pro riat e d ring t es ing

10.2 Measurement of sound

The time-a e ag ed A-weight ed one-third-octa e-ban SPL from 3 5 Hz t o 5 0 0 Hz shal be det ermined

at each mic o hone p sition b a e a ing o e each ro d segment of 2 m This forms the b sis for al

furthe ev luations It is man at ory t o measur one-third-octa e-ban fr q ency spe tra No sep rat e

measur ment of o e al SPL is r q ir d

The time-a e ag ed SPL for an in ivid al one-third-octa e b nd with the c ntr fr q ency fmeasur d

at mic o hone p sition m at the w he l track w for the ro d segment with the index i in the run r using

the tyr t and measur d at r fe enc spe d v

10.3 Proc edure for stud y of typical r oad section

The folowing r q ir ment a ply if the purpose of the measur ment is t o o tain a CP level w hich is

r pr sentative of a ro d se tion ( i.e seve al conse utive ro d segment )

Aft er el minating the ro d segment for w hich the t es r q ir ment ar not met e.g d e t o b ckgrou d

noise or t oo much deviating spe d, se 1 3, las p ra ra h), a ro d se tion shal be conside ed as

pro e ly measur d, i.e the run ac ept ed, if at leas half of the ro d segment , with a r asona le spr ad

o e the entir se tion, ha e be n measur d u de ac epta le con itions Howeve , no les than five

such segment shal be pro e ly measur d

F or each t es con ition, at leas two ru s in one or b th w he l tracks co e ing the ro d se tion in

ac ordanc with the pr vious p ra ra h shal be made If the two A-weight ed o e al levels r pr senting

the ro d se tion (one pe ru ) dife b mor than 0,5 dB for one tyr , at leas two new ru s shal be

made for that tyr The final r sult pe tyr is then the arithmetic a e ag e of al the runs or tracks

NOTE 1 Where simultane us me surements are made with the same ty e of tyre in b th whe l tracks, if

the diference b tween the two tracks ex ce ds 0,5 d , it is pos ible that this do s not in icat e an er one us

me surement,but rather a syst ematic track-t o-track diference

Spe ds can sometimesbe ome to high an sometimes to low d e to r s rictionsimposed by othe

v ehicles in the traf ic and th s do not me t the r q ir ment of 1 8.2 Discard data col e ted at

such spe ds

NOTE 2 T is subclause do s not ap ly t o the survey method des rib d in An e G

10.4 Minimum number of runs for very shor t road sections

A ro d se tion consis s of a n mbe of ro d segment (normaly at leas f ive) Whe e the a aia le t es

se tion is only 2 m t o 1 0 m (plus ru -in, se Clause 7), measur ment ac ording t o this document

can s i be made, but the n mbe of ru s shal be suff icient t o give a t otal measur d dis anc of at leas

2 0m The n mbe of such r peat ed ru s an the length of each ru shal be r p rt ed ex lcitly

10.5 Lateral position on the r oad

Unles the clent has othe r q ir ment , measur ment shal be made in one or b th w he l tracks of

the t es lane S le tion of the w he l track ( if only one is chosen) ma be made b sed on safe driving of

the vehicle The sele t ed w he l track (lef or right) shal be r p rt ed

F or othe purp ses, e.g s u y of lat eral in omog eneity of the surfac , measur ment ma be made in

othe lat eral p sitions In this case, the r sult shal clearly identify the lat eral p sition of the t es tyr

S e furthe the discus ion in F.3

10.6 Long itudinal position on the road

The longitu inal p sition on the ro d of the tes ed se tion(s ) is normal y dete mined ac ording

to the r q ir ment of the clent It is g od practic to fol ow the sug es ions r g rding position

monitoring in 6.5

10.7 Consideration of distur bing noise

Given that the t es vehicle has be n designed ac ording t o the r commendations in An ex E and has

be n c rtif ied ac ording t o An ex A, the e ar s i l seve al sour es of dis urbing noise w hich might

afe t noise levels d ring measur ment These inclu e:

— win -in uc d noise, p rticularly on non-enclosed sy st ems;

— backgroun noise from u r lat ed sour es such as p s ing vehicles an r fle tions a ains ro dside

o je t

Mor sour es of dis urb nc and advic on how t o r d c the efe t of these ar pr sent ed in F.4

R oad segment w he e noise levels ar conside ed as dis urbed or pot entialy dis urbed shal be fla g ed

for lat er proc s ing ( e Clause 1 )or discarded immediat ely, as a pro riat e

10.8 Test vehicle spe d

10.8.1 Referenc e spe ds

Pr fe r d r fe enc spe ds ar 5 km/h, 8 km/h an 1 0 km/h The actual r fe enc spe d( ) shal

alway s be not ed

10.8.2 Test spe d and ac c eptable deviatio s

During each ru the actual spe d of the vehicle shal be measur d F or each ro d segment, the t es

spe d is the a e ag e vehicle spe d over that ro d segment

The actual t es spe d on each ro d segment shal not deviat e from the r fe enc spe d b mor than

± 5 % In ad ition, the a e ag e spe d o e al ru s an o e a t est ed ro d se tion for a given tyr shal

be within ± % of the r fe enc spe d Make a cor e tion t o the measur d sou d pr s ur level t o

adjus it t o cor esp n t o the r fe enc spe d ( e Clause 1 )

In orde t o a oid dis urbing noise, espe ialy for self-p we ed t es vehicles, it is pr fe a le t o use the

highes g ear at w hich the vehicle an it spe d control fu ction wel

10.9 T yr e loads

The s atic lo d of the t es tyr ( ) shal be 3 2 0 N ± 2 0N pe tyr

10.10 T yre inflation

The t es tyr ( ) shal be inflat ed t o 2 0 kPa ± 1 k a, in cold con ition C ld con ition is w hen the

t empe atur of the tyr is close t o the ambient t empe atur , i.e the tyr has not yet be n signif icantly

warmed-up b rol ng If the inflation has t o be chang ed subs antialy t o o tain this v lue, then a se on

che k of the inflation shal be made aft er a pro imat ely 2 min t es (with tyr at r s )

The pr fe r d inflation g s is nitrog en The r asons ar that nitrog en inflation r d c s the leakag e

of g s and th s r d c s the ne d for inflation adjus ment It also causes slowe chang e in the tyr

rub e comp un pro e ties than air an the inflation pr s ur chang e d ring the warm-upproc s is

normal y lowe than if air containing some h midity is used S e R efe enc [4] for furthe information

The se on -bes choic of inflation g s is dry air, sinc h midity in air influenc s the inflation pr s ur

s a i ty

If neithe nitrog en nor dry air is a ai a le, normal air ma be used

The lo d (1 9) an inflation v lues ar a plca le t o the use of r fe enc tyr s P1 an H1 only If othe

tyr s ar used, inflation ma ha e t o be dife ently ada t ed t o the lo d;for ex mple, using the guidelnes

in R efe enc [1 ], An ex 3, p ra ra hs 2.5.2 an 2.5.3

10.11 Temperatur e me surement

10.1 1 General

Measur ment of air t empe atur ar man at ory, w he eas measur ment of ro d surfac t empe atur

ar r commen ed as a sup lement

The t empe atur measur ment shal be con uct ed close in time t o the sou d measur ment, eithe

contin ously or int ermitt ently, an the r sult r p rt ed rou ded t o the near s degr e Celsius

If p s ible, it is r commen ed that t empe atur measur ment be made contin ously It is then

r commen ed that t empe atur r adings be taken in synchronization with the noise level

measur ment , i.e pe each ro d segment and in ex ed in the same wa

If t empe atur measur ment ar made int ermitt ently, each t empe atur measur ment shal ha e a

d ration suff icient t o g et a s a le r ading of the ins rument Tempe atur s shal be measur d at leas

onc for each ro d se tion at a location r pr sentative for that se tion

It is pr fe r d that the sensor() be plac d on the t es vehicle If this is not practical or pos ible, the

t empe atur ( ) shal be measur d at the way side as close t o the ro d asis p s ible an safe

It has be n foun in r sear h in ar as with a lot of high-rise buidings that ro d surfac t empe atur

ma be a bett er v ria le t o b se t empe atur cor e tions on (R efe enc [5]) The efor , in such

environment it is highly r commen ed that b th air and ro d surfac t empe atur be measur d

NOTE Surface temperature, especialy, can vary substantialy along a test section depen ing on diferent

shading of tre s, mou tains, buildings,etc as wel as on c os -win s an surface light-a sorbing properties

10.1 2 A ir temperature

L cat e the t empe atur sensor so that it is uno s ruct ed an safe, an in such a wa that it is ex osed t o

the airflow and prot ect ed from dir ct solar radiation The latt er ma be achieved b a shading sc e n

The sensor shal be positioned 0,5 m t o 1,5 m a o e ro d surfac level

10.1 3 Road sur fac e temperature (o tio al

Position the t empe atur sensor w he e the t empe atur is r pr sentative of the t empe atur in the

w he l tracks

10.12 Over view and summary

An o e view an summary of al major measur ment p ramet ers is pr sent ed in An ex I

11 A nal ysis procedure

11.1 Definition ofsteps in the calculation proc es

The primary r sult is L

L

wri fmv

r ef, , ,

Annex C pr sent a detai ed br ak down of the calculation proc d r s and in

Annex N a flowchart i us rat es the measur ment an analy sis proc d r s that ha e t o be con uct ed

t o ar ive at a final r sult

A somew hat a ridg ed ex lanation of the calculation proc d r s is as folow s:

a) In each one-third-octa e b n , calculat e the ene g -b sed a e ag e of front an r ar mic o hone

SPLs (mic o hones 1an 2in Figur 1)

b) Ap ly the devic depen ent cor e tion C

d,f( e A.2)

c) C lculat e the o e al SPL for a segment from the one-third-octa e-ban SPLs from 3 5 Hz t o

5 00 Hz (omit this st ep if one-third-octa e-b n levels ar desir d)

d) Ap ly a spe d cor e tion for deviations from the r fe enc spe d of B times the lo arithm of the

q otient of the actual an the r fe enc spe d The v lueof thespe d coeff icient B shal be:

— B = 2 for a p rous p vement in r latively new con ition, or olde but with no seve e clo ging;

— B = 3 for a clo g ed porous, semi-p rous or dense asphalt p vemen

— B = 3 for a (non-porous)c ment conc et e p vemen

— B = 3 for al othe cases, inclu ing cases w he e the p vement y e is u k own

To help dis inguish betwe n cases, one ma conside a p vement as “ porous” (an not clo g ed) if

air v ids ar ≥ 8 % If air v ids ar un nown or diff icult t o es imat e, sele t B =3

The ex e ienc is that B v ries o e a rang e of 2 t o 40 depen ing on t es tyr an p vement ty e

It is p s ible for a use t o det ermine b his or he own measur ment a spe if ic B for a spe ific

combination of tyr an p vement Howeve , the u c rtaintiesas ociat ed with such measur ment

ar such that they rar ly give v lues for B close t o the true v lue than those given using the

default v lues a o e, w hich ha e be n det ermined b sed on a larg e n mbe of measur ment The

r sulting e ror in the cor e tion is negl gible in r lation t o othe measur ment e rors The efor ,

this document r q ir s the use of the v lues lst ed in the for g oing

1) A s specified in ISO/TS 1 8 9-3.S e the Introd ction

e) Ap ly t empe atur coeff icient γ

tfor deviations from the r fe enc t empe atur The coeff icient

for tyr P1 an tyr H1 ar given in ISO/TS 1 47 -1; for othe tyr s, coeff icient wi ha e t o be

det ermined onc the tyr s ar sele t ed

NOT 1 Ple se not e that the influence may freq ently amou t to as much as − d per 1 °C deviation

in air temperature, se also R eference [17] Substantial er or , therefore, could oc ur if no cor ection is

ap lied

f) Ap ly cor e tion for the rub e hard es of the r fe enc tyr s b sed on hardnes coeff icient β

t

The coeff icient β

t

is given in ISO/TS 1 8 9-3

g) R oad segment w he e noise levels ar o viously dis urbed b win gus s or b noise from othe

sour es, such as p s ing vehicles, shal be discarded ( e F.4)

h) Ave ag e arithmeticaly o e r maining ro d segment

i) Ave ag e arithmeticaly o e eithe r peat ed runs in a single w he l track or ru s in lef and right

w he l tracks, as a pro riat e, t o det ermine the CP levels, L

C X

j) Calculat e indic s L

C X:P, L

C X:H

or L

C X:I

as a pro riat e, b sed on the r sult of in ivid al r fe enc

tyr s P1 an H1 an the chosen r fe enc spe d

Optional y, fr q ency spe tra can be o tained b omit ing st ep c) an pe forming al calculations b sed

on one-third-octa e-ban levels

The e is a smal dife enc betwe n the t otal o e al level of the spe trum and thecalculat ed o e al level

ac ording t o the proc d r desc ibed in the for g oing S e Ta le C.1 for an ex mple It isr commen ed

that the dife enc be calculat ed an the spe tral levels cor e t ed with this dife enc v lue In mos

cases, this cor e tion is only a few t enths of a de ibel

NOTE 2 Guidance is provided for the user in 1 2 t o 1 4 on navig ting through al cor ection an avera ing

proced res in the cor ect order If this order is not fol owed, results can difer When ap ropriately ap lied in

sof ware, these formula are useful an practical in order to o tain reprod cible results

11.2 Results ex pr es ed as overal levels

NOTE The symb l “lg” stan s for the common lo arithm (b se 1 ) ac ording to ISO 8 0 0-2

Next, the devic -depen ent cor e tion fact or C

d,f

is a pled t o thea e ag e spe trum an the A-weight ed

o e al level from 3 5 Hz t o 5 0 0 Hz, w he e spe d-, t empe atur - an rub e hard es -cor e t ed level

o e a segment is calculat ed as folow s:

v

wri

ilg

an H1 ar given in ISO/TS 1 8 9-3 ( ame coefficient for both tyr s)

The v lues of the t empe atur coeff icient γ

t, w hich ar neg tive, ar given in ISO/TS 1 47 -1 if the

r fe enc tyr s P1 an H1 ar used ( ame coeff icient for b th tyr s)

The next st ep isa e a ing o e segment , w he l tracks and ru s, ac ording t o one of the folowing two

o tions:

a) case A: f irs a e a ing o e segment within one ru an then o e the lef an right w he l tracks

(w =1, 2);

b) case B: firs avera ing each segment o e b th w he l tracks (w = 1, 2) an then a e ag e o e the

segment v lues within one ru

Case A is used w hen measuring with only one tyr at a time an case B (pro a ly mor common) w hen

measuring with two paralel tyr s at a time

r

n

ir

is ex r s ed as fol ows, for the

case w hen r fe enc tyr P1 (ISO/TS 1 8 9-3)is used, an w hen v

is ex r s ed as folows, for

the case w hen r fe enc tyr H1 (ISO/TS 1 8 9-3) is used, and w hen v

11.3 Results ex pr es ed as one-thir d-octave-band levels

11.3.1 General

F or measur ment r sult ex r s ed as one-third-octa e-b n levels the calculation proc d r is

sl ghtly dife ent sinc no summation o e the one-third-octa e-b n levels is ne ded The proc d r

then is as folow s The f irs st ep is ene g a e a ing of the spe trum at mic o hones m = 1 an m =2:

an H1 ar given in ISO/TS 1 8 9-3 ( ame coefficient for both tyr s)

The v lues of the t empe atur coeff icient γ

t, w hich ar neg tive, ar given in ISO/TS 1 47 -1 if the

r fe enc tyr s P1 an H1 ar used ( ame coeff icient for b th tyr s)

Thenext t epis a e a ing o e segment , w he l tracks an ru s, ac ording t o case A or case B

n

w

n

rw

1

ir

rn

11.4 Correction for anal ysis of spectral levels

Due t o the chang ed orde of lnear a e a ing an ene g summation, the A-weight ed o e al level

v

r ef

[r fe t o C.8 an F ormula (C.1 )] To ac ou t for this dife enc , the spe tral b n s ar cor e t ed with

that dife enc :

11.5 Ac oustic variabi ity

The acous ic v ria i ty is conside ed t o be an in ication of ro d surfac homog eneity of the surfac If

r q ir d, the acous ic v ria i ty, s

t, shal be calculat ed ac ording t o Annex H

The s

t

v lue shal then be r p rt ed t og ethe with the length of the t otal t es se tion an the calculation

method used ( e Annex H)

12 Measur ement unc er tainty as es ment ac c ording to ISO/IEC Guide 98-3

The measur ment proc d r desc ibed in this document is afe t ed b seve al influencing fact ors

that lead t o v riation in the r sult o se ved for the same subje t The sour e an natur of these

pe turb tions ar not complet ely k own The measur ment u c rtainty shal be det ermined in

complanc with ISO/IEC Guide 9 -3

A ccording t o ISO/IEC Guide 9 -3, each signif icant sour e of unc rtainty ne ds t o be identified an

cor e t ed for The folowing sour es of unc rtainty ha e be n identif ied an r q ir proc s ing

ac ording t o the proc d r spe if ied in ISO/IEC Guide 98-3:

— unc rtainty d e t o o e ational v riations;

— ins rumentation u c rtainty;

— unc rtainty d e t o ext ernal dis urb nc s

R efe t o Annex K for an ex mple of a q antitative analy sis

The g ene al ex r s ion for the calculation of the CPX level, L

v

C X:t,

r ef, at a c rtain r fe enc spe d v

is an input q antity t o alow for any unc rtainty d e t o u want ed contributions from

the t es vehicle an t owing vehicle;

δ

6

is an input q antity t o alow for any unc rtainty d e t o the sele t ed r fe enc tyr

This is inclu ed he e but sinc it v lue depen s on the tyr , r fe t o ISO/TS 1 8 9-3

for the q antity t o inclu e in this calculation If othe tyr s than those spe if ied in

ISO/TS 1 8 9-3 ar used, this q antity ne ds t o be spe if ied b the use

The v lue of these input q antities shal be ev luat ed b the t es o e at ors b the proc d r given in

ISO/IEC Guide 9 -3 It can be b sed on exis ing s atis ical data, analy sis of t ole anc s s at ed in this

document an engine ring ju g ement The information ne ded t o de ive the o e al u c rtainty is given

in Ta le 3 Ta le 3 inclu es sensitivity coeff icient c

j, the v lues of w hich ar b sed on the proc d r s

an formulae used t o o tain the f inal r sult, as spe ified in ISO/IEC Guide 9 -3

The es imat e of the measuran CP level, denot ed b y, is det ermined from a se ies of q antities X

The ex an ed u c rtainty U is determined b m ultiplying the combined s an ard u c rtainty u(y)b the

a ppro riate co e age factor (k) for the chosen co e age pro a i ty as desc ibed in ISO/IEC G ide 9 -3

Table 3— Uncertainty budg et for the determination of the CPX level

Combined stan ard u certainty, u(y)

K.4 gives a detaied l s ing of the s an ard unc rtainties an sensitivity coefficient of each sour e an

gives ty ical v lues Using thesev lues, the u c rtainty bu g et analy sis r sult in a combined s an ard

unc rtainty in the CP level of 0,5 d

Ta le 4 pr sent the ex an ed unc rtainty an co e ag e pro a i ty in the case w he e the method is

a pled an individ al sour e u c rtainties ar consist ent with Ta le K.1

Table 4 — Estimated ex anded uncertainty for a co erag e pro abiity (based o Table K.1)

NOTE 1 Uncertainty d e to the reference tyre(s) is not inclu ed in the calculations in Ta le 4 R efer t o

ISO/TS 1 8 9-3 for information a out he u certainty d e t o the tyres specif ied there

NOTE 2 T e temperature cor ection depen s to some e tent on the tyre used In this document he u certainty

calculation is b sed on the as umed temperature cor ection for the P1 tyre

NOTE 3 T e u certainties presented here are valid only for the man atory mic op one positions m = 1 an

m = 2 For the other mic op one positions, ad itional u certainties might b present

13 Repeatabi ity and r eproducibi ity: System comparison acc or ding to ISO 5725-2

Conformity of ro d surfac acous ical pro e ties with national s andards is che ked b means of CP

t es s In such cases, r la i ty of the measur ment sy st ems in use in a cou try or r gion is che ked

b r gular comp rison of the CP sy st ems The ac uracy of the measur ment sy st ems shal in that

case be det ermined b the method spe if ied in ISO 5 2 - 2 The r sult can be ex r s ed in t erms

of r prod cibi ty an r peata i ity v lues The r prod cibi ity is as umed t o be comp sed of a

r peata i ty an la orat ory comp nent leading t o a model w he e

w he e

Y is themeasuran ;

μ is theo e al mean;

b is thela orat ory comp nent of the bias u de r peata le con itions;

E is theran om e ror u de r peata le con itions

The comp nent b can be es a l shed with a r gional or national org niz d roun -ro in t es of CP

sy st ems an can be at ribut ed as a cor e tion t erm t o a measur ment y st em in orde t o minimiz the

bias d e t o a c rtain measur ment y st em R efe t o ISO 5 2 - 2 for the set-up of such an ex e iment an

the proc s ing of data

14 Test r eport

The t es r p rt hal inclu e the fol owing data (man at ory, u les in icat ed othe wise)

General information

1) Time of da and dat e of measur ment

2) Org nization an o e at ors r sponsible for the measur ment

3) Purp se of the t es

4) Ty e of measur ment eq ipment (inclu ing tes vehicle, any extra tes tyr , cal brator, sou d

level mete or eq iv lent sys em, measuring eq ipment for meteorolo ical data, mic o hone

positions used)

5) Ce tification of t es eq ipment, i.e the vehicle sy st em, as t est ed in An ex A (r fe t o some publcly

a ai a le document pr senting ty es of t es s an r sult )

Informatio relating to the location and appe rance of the test site

6) Location of the t es sit e an information a out lat eral p sition of t est ed track (w he l track an

lane), as wel as the measur d dis anc ( tart and en p sitions, t es se tion length) If a ai a le, it

is g ood practic t o inclu e g eo ra hical co rdinat es of the s art an end of each sit e

Informatio relating to the type and co struction of the tested surface

7) Ty e of surfac [dense asphalt conc et e (DAC), st one mas ic asphalt ( SMA), et c.], inclu ing any

s an ardiz d or othe wise commonly used designation of the surfacing an as much as pos ible

design data such as ma imum chip ing (a gr g t e) siz , thick es of surfac la e , r sid al air

v ids cont ent, soun a sorption coefficient depen ing on w hat ty e ofinformation is a pro riat e

9) A ttachment with surfac spe ification (work r cipe or eq iv lent) sup led t o the contract or w ho

has laid the surfac ( if a ai a le)

Informatio relating to the condition of the tested surface and to enviro mental factor

1 ) Ag e of the surfac an s at e of maint enanc (w he e a aia le)

1 ) Any spe ial surfac tr atment w he e a pro riat e)

1 ) Any a pro riat e not es r g rding the homog eneity of the surfac

1 ) Numbe of day s sinc the lat es pr cipitation oc ur ed ( in case of p rous surfac only and if

a ai a le)

14 ) Ave ag e air t empe atur s (man at ory) an a e ag e ro d surfac t empe atur s (o tional) o e each

t est ed ro d se tion

Test tyre and othe test co ditio s

1 ) Tes tyr s used, identif ication of tyr s an dat e ofman factur

1 ) The t empe atur cor e tion coefficient γ

tused in the t empe atur cor e tion proc d r

1 ) R ub e hard es of the t es tyr s (no mor than 3 months old v lues)

1 ) The n mbe of runs on w hich the L

2 ) The actual measur d t es spe ds, asan a e ag e o e a t es se tion

Me sured and calculated so nd pres ure level data

v

C X:P

r ef,

v

C X :H

r ef,,

cor e t ed for t empe atur

24 ) The ex an ed u c rtainty of the t es r sult t og ethe with the co e ag e pro a i ty (o tional)

Other

2 ) The spe d coefficient B used for spe d cor e tions

2 ) Fr q ency spe trum asdet ermined from F ormula (1 ) (o tional)

2 ) Detai s of spe ial pro isionstaken t o ensur conformity with this document

Example of useful graphs or tables (o tional

2 ) The spe d r corded along the t es se tion

2 ) L

C X

r corded for one or b th r fe enc tyr s along the tes se tion (eithe one run or avera e of

al ru s)

S e Annex O w hich inclu esan ex mple of a complet ed r p rt form

Figur 2 show s an i lus ration of a single measur ment L

C Xalong an 8 0 m long ro d se tion,

with in ications pe each 2 m segment, an with one segment subje t t o a dis urb nc If al the

measur ment for this case (normaly two ru s) ar averag ed, one o tains the CP level

NOT T e noise level s ale is on the lef side of the g rap an the spe d s ale is on the right T e nominal spe d

was o viously 9 km/h in this case, which is not one of the r efer ence spe ds

Figure 2— I lustration of a me surement alo g an 800 m long road sectio , with indications of

CPX level (cor ected for spe d) and actual spe d per e ch 20 m se ment

A nnex A

(normative)

Noise from the p we u it of the measuring vehicle or it t owing vehicle shal be below the b ckgrou d

noise r q ir ment in this an ex d ring t es ing The sou d r fle tion efe t of the vehicle b dy, the

enclosur an sup orting s ructur s shal me t the r q ir ment in this annex Design c it eria w hich

shal be met t o as is the t es vehicle in me ting these pe formanc r q ir ment ar pr sent ed

The tes vehicle an measur ment sys em pe formanc shal be c rtified prior to the initial use of

the sys em

Subseq ent c rtif ication of the enclosur an tyr an w he l algnment shal be r peat ed at leas onc

eve y two years Thisma r q ir r plac ment of ag ed or damag ed comp nent prior t o r -c rtif ication

F or the two man at ory mic o hone positions, the r q ir ment shal be met as an a e ag e, but r p rt ed

data shal also inclu e r sult for the in ivid al mic o hones The r q ir ment shal also be met for

any othe o tional mic o hone p sition used The desc iption and the r sult of the t es s pe formed

shal be r p rt ed in a publcly a aia le r port

A 2 Sound reflections against an enclosure (ifany) and other objects close to the

micr ophones

A 2.1 P erfor mance requirements

Measur ment shal be made t o det ermine the influenc of sou d r fle tions on the measur d sou d

pr s ur levels in the one-third-octa e b nds from 3 5 Hz t o 5 0 0 Hz Such r fle tions could oc ur

a ains an enclosur aroun the t es tyr an the mic o hones ( if any) or a ains o je t such as tyr

a le, frames, mic o hone holde s or tyr housing ( if any), in the vicinity of the mic o hone R efle tions

a ains the t es tyr an the t es surfac ar not conside ed he e The r sulting efe t shal be r p rt ed

in eve y one-third-octa e ban from 3 5 Hz t o 5 00 Hz

In al one-third-octa e b n s from 3 5 Hz t o 5 00 Hz, the efe t of u want ed r fle tions shal not be

larg er than 3,0 d

S e also An ex E

A 2.2 Certification test method

The t es tyr an it w he l ar r plac d b an artif icial sou d sour e man factur d t o have

a pro imat ely the same g eometry an exhibiting simiar sour e g eometry, with the main sour e close

t o theleading and trai ng edg es of the tyre /ro d contact ar a A spe ification is given in A.2.3

Pr fe a ly the mic o hones an artif icial sou d sour e shal be mount ed on a single plat e in orde t o f ix

the r lative locations of the soun sour e an the r c ive s The plat e shal be t otaly soun r fle ting

Then a ply the folowing t es proc d r :

— Whie othe p rt of the CPX vehicle r main as they ar mou t ed w hen making measur ment ,

a ply a w hit e or pin noise signal t o the artif icial sou d sour e an measur the soun signal at the

two mic o hone p sitions u ti a s a le level is o tained

— Next pe form the same measur ment, but now with the artif icial sou d sour e in a hemi-ane hoic

environment trip ed of al p rt of theCP vehicle

— Calculat e the one-third-octave-b n level for each mic o hone p sition Then calculat e the ene g etic

a e ag e o e the two mic o hone p sitions in both the original an the hemi-ane hoic environment

— Subtract the one-third-octa e-b n spe trum in the original p sition from the spe trum in the

hemi-ane hoic environment

— R epeat the measur ment If the deviation in any one-third-octa e b n betwe n the f irs an the

se on r sult is larg er than 0,5 d , do a third measur ment and a e ag e those r sult that ar

within 0,5 d

The f inal r sult def ines thedevic cor e tion C

d,f

F or a two or multi-w he l trai e , pe form the c rtif ication t es at each sep rat e w he l and r p rt the

spe trum of C

d, f

for each w he l separat ely

NOTE “Whe l” me ns the rim an the whe l dis , ac ording t o ISO 3 1 T e tyre is mou ted on the whe l

A 2.3 Specifications for the artificial sound sourc e

F or radiation of sou d in the t es method for soun r fle tions, it is suita le t o use a “ tan ard” ,

artificial soun sour e An ex mple of such a soun sour e is pr sent ed in Figur A.1 Figur A.2 furthe

i lus rat es how this soun sour e can be r alz d It is advised t o plac the tyr mock-up on a plat e

simulating the ro d surfac an also t o f it a w he l inside the simulat ed tyr w hich is the same as the

w he l used for the r fe enc tyr ( ), as shown in the right p rt of Figur A.2 Of course, the enclosur or

any othe larg e o je t near the r fe enc tyr shal also be fitt ed in a p sition r lative t o the tyr

mock-up r pr sentative of on-ro d measur ment

It isr commen ed that the mic o hones, b se plat e, tyr mock-up an sou d sour e be b lt ed t og ethe

int o a single sy st em, so that mo ing the set-up does not cause chang es in the g eometry, sinc such

chang es easi y jeo ardiz the r q ir ment of 0,5 d r peata i ty

This mock-up can be the same for b th tyr P1 an tyr H1, although they dife a lt le in dimensions

The use of this p rticular sou d sour e is o tional, although it is r commen ed that the one pr sent ed

or something simi ar be used

A 3 Backg round noise from the test vehicle itself or its operation

A 3.1 Desig n requirements for the mounting of the test tyre(s)

Tes tyr () shal not be mou t ed on a st ee ed a le or on an a lethat is driven d ring the measur ment

Tyr s on the t es vehicle othe than t es tyr s shal be of the q iet es design a ai a le, w hie s i l

maintaining the a pro riat e safety s an ards

Any brakes close t o the t es tyr () shal be in such con ition that they ar t otal y r leased w hen

measur ment ar made

Sup orting tyr s on a trai e ( if a pro riat e) ma be of a spe ial nar ow ty e t o r d c tyre /ro d noise,

if p s ible

Dimensions in milimetr es

NOTE T e whe l width is in icat ed as the stan ard designation 6.5 J

Figure A.1 — Outl ne of a recommended tyre mock-up with artificial so nd sour e suitable for

testing the efect of so nd reflectio s (example)

NOTE For lou spe ker mou ting an dimensions, se Figure A.1 T e right part of the f igure shows how

reflective con itions may b improved by mou ting a whe l in the mid le

Figure A.2 — Examples of tyre mock-up for artificial so nd so r e

A 3.2 P er formanc e requir ements

The unwant ed noise (b ckgrou d noise, inclu ing air flow noise) of the entir t es vehicle sy st em shal

not influenc one-third-octa e-b n levels b mor than 1,0 d in the 5 0 Hz t o 5 0 0 Hz fr q ency

rang e an mor than 2,0 d in the 3 5 Hz t o 40 Hz rang e

NOTE Since it is u likely that al freq ency b n s are influenced by 1 d at the same time, this req irement

is as umed t o b ap ro imat ely eq ivalent o at le st 1 d signal/noise ratio in overal A-weight ed levels

A 3.3 Certification test methods

A 3.3.1 General

Thr e alt ernative methods (A.3.3.2 t o A.3.3.4) ma be used

NOTE With re ard to air flow noise, some p blished data may b useful, such as R eference [16] A French

stan ard, R eference [2 ], inclu es a method for determining air flow noise

A 3.3.2 Lifed/remo ed tyr e metho

Whe e the t es vehicle cons ruction makes this practical, a useful method is t o pe form a t es w he e the

measuring tyr is l ft ed up a o e the ro d surfac or r mo ed from the t es vehicle The r sulting level

is comp r d with that from normal measur ment with tyre / ro d contact If the o e al A-weight ed

level is then r d c d b at leas 1 d in r lation t o w hen the vehicle is eq ip ed with it r fe enc tyr s

ru on the mos “q iet” ro d surfac t o be s u ied, an the one-third-octa e-ban levels ar r d c d

b at leas 6 d in the 5 0 Hz t o 5 0 0 Hz fr q ency rang e (4 d in the 3 5 Hz t o 40 Hz rang e), then

the r q ir ment a o e is met Howeve , in this method the bearing noise is not measur d in lo ded

con ition, w hich would then r q ir an extra t es An up e l mit t o the bearing noise can be o tained

b ru ning the t es tyr , inclu ing it normal bearing, on a la orat ory drum using a smo th tyr an a

smo th st eel drum

A 3.3.3 Laborator y dr um metho

This method is p rticularly r commended for four-w he led self-p we ed vehicles, for w hich the

l ft ed/r mo ed tyr method (A.3.3.2)cannot be a pled The tyr s of the vehicle, mou t ed as in normal

o e ating con itions, ar run in a hemi-ane hoic ro m conse utively on a la orat ory drum, ha ing a

diamet er of at leas 1,7 m, co e ed with an artificial ro d surfac , an their sou d contribution in the

measur ment mic o hones is r corded The surfac is r commen ed t o be an ep x r plca of a surfac

ac ording t o ISO 1 84 The drum shal be a le t o lo d the p we unit of the vehicle t o a pro imat ely

ty ical lo d of the engine d ring cons ant-spe d driving on a ro d This t es is pe formed separat ely for

thr e dife ent conf igurations:

a) thet es tyr ru alone;

b) theothe tyr of the same a le ru alone ( his isp s ible only if the t es a le isnot p we ed);

c) thetwo tyr s of the othe (driven) a le run t og ethe

In the third con guration, the vehicle is p we ed an the mos r lev nt g ear set ing for the t es spe d

is used, an the engine spe d is pro r s ively inc eased unti the engine begins t o drive the drum The

noise level then t o be r corded is that cor esp n ing t o the highes engine spe d s i l me ting this

r q ir men it ac ount for the influenc of the tyr s of the driven a le an the engine t og ethe The

noise levels measur d in the two las conf igurations ar ene g eticaly ad ed If the r sulting A-weight ed

level is at leas 1 dB lower than the A-weight ed level measur d in the f irs conf iguration, an the

r sulting one-third-octa e-b n levels ar at leas 6 d lowe within 5 0 Hz t o 5 0 0 Hz (4 dB within

3 5 Hz t o 40 Hz), then the r q ir ment a o e ismet

A 3.3.4 Customized metho

Any othe method designed in ac ordanc with g ood acous ical practic ma be used, pro ided

it is ju g ed t o be as g ood as or bett er than the methods in A.3.3.2 an A.3.3.3, an pro ided it gives

as a r sult the influenc of b ckgroun noise on the sou d measur d in the s an ard mic o hone

p sitions This method could for ex mple inv lve det ermination of inse tion los of the enclosur ( if

any) combined with measur ment u de some r pr sentative con itions of the contribution of each

p t ential b ckgrou d noise sour e If the cust omiz d method is used, it shal be clearly not ed in the

c rtification r p rt w hy it is bett er than any of the othe methodsan how this is achieved

A 4 Backg round noise from towing v hicle

A 4.1 S ur c es of noise

Noise sour es on thet owing vehicle ma inclu e, in particular, the folowing:

Powe u it n i s e : Mos sour es of power u it noise ar lkely t o be locat ed at the front of the t owing

vehicle an can then normaly be negle t ed Howeve , oft en the exha us outlet an the r lat ed si enc r()

ar locat ed at the r ar of the t owing vehicle an ma then contribut e t o the b ckgrou d noise This is

of p rticular importanc w hen the vehicle is ru ning with an engine lo d w hich is highe than d ring

“ normal” o e ation of thisvehicle an in the lowe fr q ency rang e

Tyre/ro d n i s e: Depending on the dis anc betwe n the t owing vehicle an the mic o hones, tyre /ro d

noise from the tyr s on the t owing vehicle, espe ialy the r ar a le tyr s, ma contribut e signif icantly

t o the b ckgrou d noise The contribution ma be much mor imp rtant than w hen conside ing the

t owing vehicle tyr s an the t es tyr s as omni-dir ctional p int sour es, sinc tyr s usualy have a

dir ctivity w hich inc eases noise emis ion t owards the front an the r ar, for w hich the horn efe t

play s a leading role Not e also that tyre /ro d noise ma be highe than ex e t ed d e t o the extra slp

in uc d w hen the driving tyr s on the t owing vehicle ru at inc eased slp con itions d e t o the lo d

caused b t owing

Air turb lenc e n i s e : The air turbulenc from the t owing vehicle ma c eat e backgroun noise in the

mic o hones, espe ialy if the eis no enclosur arou d the t es tyr an the mic o hones

A 4.2 P erfor mance requirements

The r q ir ment in A.3.2shal also a ply t o any influenc from the t owing vehicle ( if a pro riat e)

A 4.3 Certification test methods

The p we unit noise, inclu ing exhaus noise, ma easi y be t est ed b ru ning the t owing vehicle

at an engine lo d ty ical of a mor “lo ded” con ition, such as w hen g oing uphi , an comparing the

mic o hone signals t o a con ition w hen the t owing vehicle engine is set at idl ng

F or tyre / ro d noise d e t o the t owing vehicle, r fe t o the t es methods for the t es vehicle F or air

turbulenc , r fe t o the not e in A.3.3.1

A 5 Backg round noise from ex ternal vehicles

A 5.1 P erfor mance requirements

The t es vehicle shal be designed in orde t o asc rtain that the influenc of othe vehicles ( in the

normal traff ic) is no mor than w hat is r q ir d r g rding b ckgrou d noise, i.e the sou d pr s ur

levels from such vehicles shal not be highe than r commen ed in F.4

A 5.2 Certification test method

The vehicle shal be t est ed u de s atic con itions, at a location such as the ro d shoulde w he e vehicles

in the r gular traff ic s r am can p s in the adjac nt lane, so that it r lative p sition is r pr sentative

of normal o e ation on publc ro ds The a e ag e spe d of the traff ic in the adjac nt lane shal be

7 km/h t o 9 km/h an the ma imum pe mitt ed dis anc betwe n the t es vehicle an the adjac nt

traff ic shal be 1,5 m

The measur ment shal be made on at leas one ro d surfac ty e As a minimum, this shal inclu e a

dense asphalt surfac (DAC or SMA) with as fine an dense t extur as is a ai a le

F or ty ical pas ing vehicles, measur the ma imum A-weight ed sou d pr s ur levels and fr q ency

spe tra in the two mic o hones of the t es vehicle, as wel as the spe d of each vehicle Inclu e in the

r sulting data ase no les than 2 p s eng er cars an 1 hea y vehicles The latt er shal be cat eg ory

2 vehicles ( rucks, buses or co ches with mor than two a les) as spe ified in ISO 1 8 9-1 Use the

time weighting F (IEC 616 2-1) Any enclosur or sc e n shal then be in the position used d ring CP

measur ment Ther fe enc spe d v

refshal be 80 km/h

Cor e t the sou d pr s ur levels ( inclu ing spe tra) for spe ds t o the r fe enc spe d of 8 km/h

using a spe d coeff icient B of 3 on the DAC or SMA surfac s, ac ording t o 1 1 C mpar measur d

sou d pr s ur levels from the r fe enc tyr ( ), on the same ty e of surfac ( ), with those of the fle t

of the pas ing vehicles

If the dife enc in t otal A-weight ed level is eq al t o or highe than 1 d , the t es vehicle q al fies for

use without any spe ial tr atment or fla ging for p s ing vehicles in in-traff ic measur ment ( e F.4),

at the r fe enc spe d of 8 km/h an highe F or r fe enc spe ds lowe than 80 km/h, the spe d of

adjac nt traff ic shal be a pro imat ely eq aly low for the q alf ication t o be v ld

NOTE T e DAC or SMA f ine-te tured surface is usualy the most “ noisy” one for the he v vehicles an

therefore gives a conservative value for the b ckgrou d noise influence

A 6 A lig nment ofthe test tyre

The cambe angle of the t es tyr ( ) shal be no mor than 1,5° an ( tatic) t oe-in no mor than ± °

These shal be che ked at leas onc eve y two years

A 7 Certification report

The r sult of the c rtification t es s, desc ibed in the for g oing, an a desc iption of thesyst em an the

pro e ties of the man at ory r q ir d it ems ( uch as acous ic lning in the enclosur ) shal be r p rt ed

in a document that is, b r q es , made a ai a le for third parties in r lation t o a c rtain measur ment

proje t, or is a aia le for ex mple for downlo d from a websit e A.2 t o A.5 shal be inclu ed in the

c rtif ication r p rt

A nne x B

(normative)

The measur d one-third-octa e-b nd levels shal be a e ag ed o e each 2 m ro d segment Avera ing

o e a segment shal be made ac ording t o the eq al-ene g principle ( ene g eticaly” Various set-ups

make use of an alow only c rtain ty es of a e a ing proc d r s, so it is ne es ary t o ac ept mor

than one ty e The fol owing ar ac epta le a e a ing proc d r s, giving es ential y simiar r sult

( e i us rations in Figur B.1)

a) Line r avera ing o e rectangular window s

b)Ex onential avera ing e ch 1/8th of a seco d with a moving ex onential wind w