prEN ISO 20500-2

SLOVENSKI STANDARD
01-september-2020
Premični stroji za gradnjo cest - Varnost - 2. del: Posebne zahteve za stroje za
rezkanje cestišča (ISO/DIS 20500-2:2020)
Mobile road construction machinery - Safety - Part 2: Specific requirements for road-
milling machines (ISO/DIS 20500-2:2020)
Bewegliche Straßenbaumaschinen - Sicherheit - Teil 2: Besondere Anforderungen an
Straßenfräsen (ISO/DIS 20500-2:2020)
Machines mobiles pour la construction de routes - Sécurité - Partie 2: Prescriptions
spécifiques pour fraiseuses routières (ISO/DIS 20500-2:2020)
Ta slovenski standard je istoveten z: prEN ISO 20500-2
ICS:
93.080.10 Gradnja cest Road construction
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT INTERNATIONAL STANDARD
ISO/DIS 20500-2
ISO/TC 195 Secretariat: SAC
Voting begins on: Voting terminates on:
2020-07-10 2020-10-02
Mobile road construction machinery — Safety —
Part 2:
Specific requirements for road-milling machines
Machines mobiles pour la construction de routes — Sécurité —
Partie 2: Prescriptions spécifiques pour fraiseuses routières
ICS: 93.080.10
THIS DOCUMENT IS A DRAFT CIRCULATED
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ISO/DIS 20500-2:2020(E)
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TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
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PROVIDE SUPPORTING DOCUMENTATION. ISO 2020

ISO/DIS 20500-2:2020(E)
© ISO 2020
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ISO/DIS 20500-2:2020(E)
Contents Page
Foreword . v
Introduction . vii
1 Scope .1
2 Normative references .1
3 Terms and definitions .2
4 Safety requirements and/or protective/risk reduction measures .2
4.1 General .2
4.2 Visibility .2
4.2.1 General .2
4.2.2 Visibility performance criteria .3
4.2.3 Visibility performance criteria for the RB .4
4.3 Operation and handling .5
4.3.1 General .5
4.3.2 Road milling machines with emission reducing device by evacuation (EVAC-ERD) .5
4.4 Operator's station .5
4.5 Stopping .5
4.6 Access system to operator's station and to maintenance points .5
4.7 Protection .6
4.7.1 General .6
4.7.2 Milling equipment .6
4.7.3 Lowering the milling equipment .7
4.8 Signal devices and warning signs.7
4.9 Electro-magnetic compatibility (EMC) .7
4.10 Noise and vibration .7
5 Verification of the safety requirements and/or protective/risk reduction measures .7
6 Information for use .9
6.1 Instruction handbook .9
Annex A (normative) Noise test code for road-milling machines . 10
A.1 Scope . 10
A.2 Determination of A-weighted sound power level . 10
A.2.1 General . 10
A.2.2 Measurement surface . 10
A.2.3 Size of the measurement surface . 10
A.2.4 Microphone positions on the hemispherical measurement surface . 12
A.2.5 Positioning of the machine . 12
A.2.6 Repetition of the test . 12
A.3 Determination of A-weighted emission sound pressure level at the operator's
position . 12
A.3.1 General . 12
A.3.2 Enclosed operator's positions . 13
A.3.3 Quantities to be determined . 13
A.3.4 Repetition of the test . 13
A.3.5 Microphone position(s) . 13
iii
ISO/DIS 20500-2:2020(E)
A.4 Operating conditions . 13
A.4.1 Fan speed . 13
A.4.2 Operating conditions for working units . 14
A.5 Uncertainty . 14
A.6 Information to be recorded . 14
A.7 Information to be reported . 14
A.8 Declaration and verification of noise emission values . 15
Annex B (informative) Examples of road-milling machines . 16
Annex C (informative) Emission reducing device by evacuation (EVAC-ERD) – Test
procedures . 18
C.1 Scope . 18
C.1.1 Purpose . 18
C.2 Terms and definitions . 19
C.2.1 Definitions for EVAC-ERD description . 19
C.3 Measurement equipment and devices. 20
C.4 General requirements . 21
C.4.1 Quality measures . 21
C.4.2 Safety precautions . 21
C.4.3 Required test-site and environmental specification . 22
C.5 Installation, qualification and operating conditions of Equipment under test (EUT) . 24
C.5.1 General . 24
C.5.2 EUT settings . 24
C.5.3 Separation Set-up . 24
C.5.4 Smoke-Test . 25
C.6 Performance-Test . 25
C.6.1 General . 25
C.6.2 Methodology and steps of measurement . 26
C.6.3 EUT-Separation-Test-Setup . 29
C.6.4 EUT-in-situ-test-Setup (NIOSH-Test, modified) . 32
C.7 Determination of capture-efficiency . 36
C.7.1 General . 36
C.7.2 Determination of EUT-Separation-test-Setup capture-efficiency . 37
C.7.3 Determination of EUT-In-situ-test-Setup capture-efficiency . 37
C.7.4 Variance and statistical significance . 37
C.8 Information to be recorded . 38
C.9 Information to be reported . 40
C.10 Declaration and verification of capture-efficiency values . 41
Annex D (informative) List of significant hazards . 43
For European version only . 47
Annex ZA (informative) Relationship between this European Standard and the essential
requirements of Directive 2006/42/EC aimed to be covered . 48
Bibliography . 53

iv
ISO/DIS 20500-2:2020(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.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
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. Details of any
patent rights identified during the development of the document will be in the Introduction and/or on
the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the World
Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see
www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 195, Building construction machinery and
equipment.
ISO 20500 consists of the following parts, under the general title Mobile road construction machinery —
Safety:
— Part 1: Common requirements
— Part 2: Specific requirements for road-milling machines
— Part 3: Specific requirements for soil-stabilising machines and recycling machines
— Part 4: Specific requirements for compaction machines
— Part 5: Specific requirements for paver-finishers
— Part 6: Specific requirements for mobile feeders
— Part 7: Specific requirements for slip form pavers and texture curing machines
A list of all parts in the ISO 20500 series can be found on the ISO website.
v
ISO/DIS 20500-2:2020(E)
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
vi
ISO/DIS 20500-2:2020(E)
Introduction
This International Standard is a type C standard as stated in ISO 12100.
The machinery concerned and the extent to which hazards, hazardous situations and events are covered
are indicated in the scope of this International Standard.
When provisions of this type C standard are different from those stated in type A or B standards, the
provisions of this type C standard take precedence over the provisions of the other standards, for
machines that have been designed and built according to the provisions of this type C standard.

vii
DRAFT INTERNATIONAL STANDARD ISO/DIS 20500-2:2020(E)
Mobile road construction machinery — Safety —
Part 2:
Specific requirements for road-milling machines
1 Scope
This part of ISO 20500, together with part 1, deals with all significant hazards for road-milling machines
when they are used as intended and under the conditions of misuse which are reasonably foreseeable by
the manufacturer associated with the whole life time of the machine (see Annex D).
The requirements of this part are complementary to the common requirements formulated in
ISO 20500-1.
This document does not repeat the requirements from ISO 20500-1, but adds or replaces the
requirements for application for road-milling machines.
The following significant and relevant hazards are not covered in this document:
— Lightning.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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 2867:2011, Earth-moving machinery — Access systems
ISO 3744:2010, Acoustics — Determination of sound power levels and sound energy levels of noise sources
using sound pressure — Engineering methods for an essentially free field over a reflecting plane
ISO 9244:2008+Amd 1:2016, Earth-moving machinery — Machine safety labels — General principles;
Amendment 1
ISO 11201:2010, Acoustics — Noise emitted by machinery and equipment — Determination of emission
sound pressure levels at a work station and at other specified positions in an essentially free field over a
reflecting plane with negligible environmental corrections
ISO 12100:2010, Safety of machinery — General principles for design — Risk assessment and risk reduction
ISO 13857:2008, Safety of machinery — Safety distances to prevent hazard zones being reached by upper
and lower limbs
ISO 15645:2018, Road construction and maintenance equipment — Road milling machinery —
Terminology and commercial specifications
ISO 20500-1, Mobile road construction machinery — Safety — Part 1: Common requirements
ISO/DIS 20500-2:2020(E)
ISO 20500-5, Mobile road construction machinery — Safety — Part 5: Specific requirements for paver-
finishers
ISO 29042-4:2009, Safety of machinery — Evaluation of the emission of airborne hazardous substances —
Part 4: Tracer method for the capture efficiency of an exhaust system
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
IEC Electropedia: available at http://www.electropedia.org/
ISO Online browsing platform: available at http://www.iso.org/obp
3.1
road-milling machines
mobile road construction machines used to mill material from paved surfaces
3.2
milling equipment/milling drum
power-driven cylindrical bodies on which the milling tools are fitted. The cylindrical bodies rotate during
the milling operation
3.3
emission reducing device (ERD)
system to extract or reduce emissions of airborne particles generated by the milling process from the
area of the operator’s stations of a road-milling-machine
3.4
emission reducing device by evacuation (EVAC-ERD)
ERD-system based on fluid-dynamic evacuation of airborne particles by technical means establishing an
accelerated air-flow or negative pressure in the rotor chamber
Note to entry: Rotor chamber as defined in ISO 15645.
4 Safety requirements and/or protective/risk reduction measures
4.1 General
Road-milling machines shall comply with the safety requirements and/or protective/risk reduction
measures of this clause. In addition, the machines shall be designed according to the principles of EN ISO
12100:2010 for relevant but not significant hazards which are not dealt with by this document.
Road-milling machines shall comply with the requirements of ISO/DIS 20500-1, as far as not modified or
replaced by the requirements of this part.
4.2 Visibility
4.2.1 General
4.2 of ISO 20500-1 applies with the following additions:
ISO/DIS 20500-2:2020(E)
4.2.2 Visibility performance criteria
The machine meets the requirements of this International Standard if the measurement results show no
maskings or maskings smaller than or equal to the performance criteria with direct or indirect view as
specified in Table 1.
When there are two operator positions on the operator’s station the resulting maskings may be a
combination (overlapping) of the individual maskings.
Table 1 — Setup of machines
Small road milling machine with
Large road milling machine conveyor Small milling machine w/o conveyor
(front mounted conveyor/operator’s station (rear or front mounted (no or very small conveyor/operator’s
on the center of the machine) conveyor/operator’s station on the rear of station on the rear of the machine)
the machine)
HH1: Height of milling drum above ground

HH2: Height of conveyor above ground
HH1: Height of milling drum above ground
HH1: Height of milling drum above ground
HH2: Height of conveyor above ground

XX: No requirements under conveyor (gap in
XX: No requirements under conveyor (gap
the RB)
in the RB)
HH1 = In transport position (minimum
HH1 = In transport position (minimum
200 mm)
200 mm)
HH2 = in a loading position (min. 3.000 HH1 = In transport position (minimum
HH2 = in a loading position (min. 3.000 mm)
mm) 200 mm)
XX = width of the conveyor + max. 150 mm
XX = width of the conveyor + max. 150 mm
on each side
on each side
ISO/DIS 20500-2:2020(E)
The distances for HH and XX shall be reported in the test report.
Table 2 — Visibility performance criteria
A B C D E F RB
Large road milling machine
205 405 405 405 405 205 405
2 – 700 and No specific No specific No specific No specific 2 – 700 and
1 – 1300 criteria criteria criteria criteria 1 – 1300
Small road milling machine with front conveyor
205 405 405 405 405 205 405
2 – 700 and
1 – 1300 1 – 1300 1 – 1300 1 – 1300 2 – 700 300
1 – 1300
Small road milling machine with rear conveyor
205 405 405 405 405 205 405
2 – 700 and
2 – 700 1 – 1300 1 – 1300 1 – 1300 1 – 1300 300
1 – 1300
Small road milling machine w/o conveyor
205 405 405 405 405 205 405
2 – 700 1 – 1300 1 – 1300 1 – 1300 1 – 1300 2 – 700 300

4.2.3 Visibility performance criteria for the RB
The machine meets the requirements of the standard if the measurement results show no maskings or
maskings smaller or equal to the acceptable maskings (300 mm) when evaluated using the eye spacing
specified in Table 2 for the RB and using the test object height for each region as specified in Table 3.
ISO/DIS 20500-2:2020(E)
Table 3 — Vertical test object height by machine type and region of rectangular boundary
Machine Type Region of the RB
Front side Left hand side Right hand side Rear side
Large road milling machine 1.5 m 1.5 m 1.5 m 1.5 m
(with gap XX under the
conveyor)
Small road milling machine with 1.5 m 1.5 m 1.5 m 1.5 m
conveyor (with gap XX under
the conveyor)
Small road milling machine w/o 1.5 m 1.5 m 1.5 m 1.5 m
conveyor
4.3 Operation and handling
4.3.1 General
4.3 of ISO 20500-1 applies with the following addition:
— to minimize the risk of dust and to minimize the risk of inhalable particles (for example silica, mineral
fibers), provisions for an ERD (e.g. a water sprinkling system, adjustable flaps, etc.) shall be made.
4.3.2 Road milling machines with emission reducing device by evacuation (EVAC-ERD)
Road milling-machines with an operating width > 1300 mm shall be so designed that in addition an
emission reducing device by evacuation (EVAC-ERD) can be fitted, if not already included in the base
design of the machine.
Annex C describes the test procedure for evaluating the capture efficiency of such an EVAC-ERD.
NOTE1 National regulations or regional requirements can apply.
NOTE 2 A width of 1300 mm is currently considered to be the threshold between rear-loader and front-loader
road-milling-machines.
4.4 Operator's station
4.4 of ISO 20500-1 applies with the following exception:
— 4.4.2 of ISO 20500-1, first paragraph, does not apply for road-milling machines.
— 4.4.3 of ISO 20500-1, does not apply for road milling machinery with an operating mass ≤ 4 500 kg.
4.5 Stopping
4.7 of ISO 20500-1 applies with the following addition:
— it shall be possible to stop the milling equipment, even while the power unit (engine) is running.
4.6 Access system to operator's station and to maintenance points
4.9 of ISO 20500-1 applies with the following addition:
ISO/DIS 20500-2:2020(E)
— provisions shall be made to minimize hazards if wheels and tracks are in the vicinity of the operator's
station and/or in the access areas. If there are guards, they shall comply with ISO 20500-1, clause
5.10.2.
4.4 of ISO 20500-1 applies with the following exemption and addition:
— an alternative exit path according to ISO 2867:2011, clause 4.3 is not required for road-milling
machines with a milling width less or equal than 1,3 m.
4.7 Protection
4.7.1 General
4.10 of ISO 20500-1 applies with the following additions:
4.7.2 Milling equipment
4.7.2.1 General
For preventing access to the milling equipment and to retain debris and ejected parts, 4.10.2 of
ISO 20500-1 applies with the additions and exceptions in clauses 4.6.2.2 and 4.6.2.3.
4.7.2.2 Rear guards
The rear guards shall be design as movable interlocked guard to stop the milling drum when opened and
shall be designed so that:
— it shall be fitted with a holding device in order to be secured while open;
— safety distances between the ground level and the lower part of the guard may be fixed by the
operator exceeding the required safety distance according ISO 13857, Annex B in order to complete
material discharge or the lowering of the milling drum adjacent to an obstacle;
— a distance guard shall be fitted on small road milling machine.
NOTE Structural parts of the machines and/or conveyors may be considered as part of the distance guards.
4.7.2.3 Side guards
Power-operated side guards of the milling drum guards, intended to be controlled during operation of
the machine, shall comply with the following design criteria:
— the controls shall not lock in any position except in neutral (hold-to-run control), see also
ISO 20500-1, clause 4.6.2.1;
— the controls shall be fitted out of danger areas and allowing the operator view to the side guards;
— a yellow flashing light shall be fitted within the danger areas and shall be activated whenever the
controls are operated;
— the power-operated side guards shall automatically return to their normal (pre-set) position when
the controls are released except when the milling drum is stopped.
ISO/DIS 20500-2:2020(E)
— The side guards shall be designed so that they can only be locked in the raised position (e.g. for
maintenance) when the milling drum is off.
4.7.2.4 Maintenance
For maintenance either a manual milling drum turning system or a maintenance mode according to
clause 4.10.2.4 of ISO 20500-1 shall be provided in order to replace the milling tools.
4.7.3 Lowering the milling equipment
The machine shall be designed to minimize the risk of unintentional movement (e.g. jumping backwards)
when lowering the milling equipment to the cutting mode.
4.8 Signal devices and warning signs
4.15 of ISO 20500-1 applies with the following addition:
— a legible and indelible warning sign (see e.g. Figure C.22 from ISO 9244:2008+Amd 1:2016) shall be
applied on both sides of the movable guards or on the protective devices, located around the milling
drum.
4.9 Electro-magnetic compatibility (EMC)
4.18 of ISO 20500-1 applies with the following addition:
— the antenna shall be located successively on the left- and right-hand sides of the road-milling
machine, with the antenna parallel to the plane of the longitudinal symmetry of the road-milling
machine and in line with the SIP.
4.10 Noise and vibration
4.19 of ISO 20500-1 applies with the following addition:
— for the determination of the noise emission values, Annex A of this standard applies.
5 Verification of the safety requirements and/or protective/risk reduction
measures
Safety requirements and/or protective/risk reduction measures of Clauses 4 and 6 of this document shall
be verified according to Table 4.
Table 4 sets out verification methods which shall be applied for each safety requirement in this document.
Where X(s) is indicated in the table, the corresponding verification method(s) shall be applied.
Table 4 shall be read in conjunction with the corresponding clauses.
Table 4 includes the following verification methods:
a) calculation: to establish that the requirements of this document have been met;
b) visual verification: to establish that something is present (e.g. a guard, a marking, a document);
ISO/DIS 20500-2:2020(E)
c) measurement: to show that the required numerical values have been met (e.g. geometric dimensions,
safety distances, resistance of insulation of the electric circuits, results of physical tests);
d) functional tests: to show that the adequate signals intended to be forwarded to the main control
system of the complete machine are available and comply with the requirements and with the
technical documentation;
e) special verification: by reference to a standard which is mentioned in the corresponding clause.
Table 4 — Verification of safety requirements and/or protective/risk reduction measures
4 Safety requirements and/or protective/risk reduction
measures
4.1 General
4.2 Visibiliy  X X
4.3 Operating and handling
4.3.1 General X X
4.3.2 Road milling machines with emission reducing device by  X X
evacuation (EVAC-ERD)
4.4 Operator's station
4.5 Stopping  X
4.6 Access system to operator's station and to maintenance X X
points
4.7 Protection
4.7.1 General
4.7.2 Milling equipment X X
4.7.2.1 General X X
4.7.2.2 Rear guards X X
4.7.2.3 Side guards X X
4.7.2.4 Maintenance X X
4.7.3 Lowering the milling equipment  X
4.8 Signal devices and warning signs X
4.9 Electro-magnetic compatibility (EMC)  X
4.10 Noise and vibration  X
6.1 Instruction handbook X
Annex A Noise test code for road-milling machines  X
Clause number
Title
a) Calculation
b) Visual verification
c) Measurement
d) Functional test
e) Special verification
ISO/DIS 20500-2:2020(E)
Annex C Emission reducing device by evacuation (EVAC-ERD) –  X
Test procedures
6 Information for use
6.1 Instruction handbook
Clause 6.2 of ISO 20500-1 applies with the following addition:
— information for a safe cleaning of the rotor compartment and the conveyor;
— Information on corrective measures to be taken, if the ERD does show improper or undesired
functions, if an ERD, is installed;
— information on how to periodically maintain the ERD, if installed;
— information on residual risks and instructions to minimize the risks (e.g. machine jumping
backwards) during lowering of the milling device.
Clause number
Title
a) Calculation
b) Visual verification
c) Measurement
d) Functional test
e) Special verification
ISO/DIS 20500-2:2020(E)
Annex A
(normative)
Noise test code for road-milling machines
A.1 Scope
This noise test code specifies all the information necessary to carry out efficiently and under standardized
conditions the determination, declaration and verification of the noise emission characteristics of road-
milling machines.
Noise emission characteristics include emission sound pressure levels at workstations and the sound
power level. The determination of these quantities is necessary for:
— manufacturers to declare the noise emitted;
— comparing the noise emitted by machines in the family concerned;
— purposes of noise control at the source at the design stage.
The use of this noise test code ensures reproducibility of the determination of the noise emission
characteristics within specified limits determined by the grade of accuracy of the basic noise-
measurement method used. Noise-measurement methods allowed by this standard are engineering
methods (grade 2).
A.2 Determination of A-weighted sound power level
A.2.1 General
This annex specifies additional requirements for the determination of A-weighted sound power level
according to ISO 3744.
A.2.2 Measurement surface
A hemispherical test area shall be used for measurement.
A.2.3 Size of the measurement surface
The radius shall be calculated from the basic length L of the machine (see Figure A.1):
ISO/DIS 20500-2:2020(E)
Figure A.1 — Basic length L
The radius shall be:
— 4 m when the basic length L of the machine to be tested is less than or equal to 1,5 m;
— 10 m when the basic length L of the machine to be tested is greater than 1,5 m but less than or equal
to 4 m;
— 16 m when the basic length L of the machine to be tested is greater than 4 m.
ISO/DIS 20500-2:2020(E)
A.2.4 Microphone positions on the hemispherical measurement surface
Six microphone positions (i.e. positions 2, 4, 6, 8, 10 and 12) shall be arranged according to Figure A.2.

Microphone
x/r y/r z
positions
2 0,7 0,7 1,5 m
4 - 0,7 0,7 1,5 m
6 - 0,7 - 0,7 1,5 m
8 0,7 - 0,7 1,5 m
10 - 0,27 0,65 0,71 r
12 0,27 - 0,65 0,71 r
Figure A.2 — Microphone positions
A.2.5 Positioning of the machine
The center of the machine shall coincide with the center of the hemisphere which is the intersecting point
of the x-axis and y-axis (see Figure A.2). The front (direction of travelling) of the machine shall point
towards the microphone positions 2 and 8. For positioning the machine, the middle of the basic length L
shall be regarded as the central point.
A.2.6 Repetition of the test
The A-weighted sound power level shall be determined at least three times. If at least two of the
determined values do not differ by more than 1 dB, further measurements will not be necessary.
Otherwise the measurements shall be continued until 2 values differing by no more than 1 dB are
obtained. The A-weighted sound power level to be used for calculating the sound power level to be
declared is the arithmetic mean of both highest values that do not differ by more than 1 dB.
The total duration of each measurement at each microphone position shall be at least 15 s.
A.3 Determination of A-weighted emission sound pressure level at the
operator's position
A.3.1 General
This annex specifies additional requirements for the determination of the A-weighted emission sound
pressure level at operator's position of road-milling machines according to ISO 11201 for a seating
and/or standing operator. The operator shall be present during the test.
ISO/DIS 20500-2:2020(E)
A.3.2 Enclosed operator's positions
When equipped with a cabin, all doors and windows shall be closed during measurement. The operator
station air circulation fan speed shall be set to mid-position.
A.3.3 Quantities to be determined
If more than one operator's position is provided, the emission sound pressure level at the operator's
station is the highest emission value determined at the operator's positions.
A.3.4 Repetition of the test
The sound pressure level shall be measured at least three times at each microphone position. If at least
two of the measured values do not differ by more than 1 dB, further measurements will not be necessary.
Otherwise the measurements shall be continued until two values differing by no more than 1 dB are
obtained. The A-weighted emission sound pressure level to be used is the arithmetic mean of the two
highest values that do not differ by more than 1 dB.
The duration of each measurement at each microphone position shall be at least 15 s.
A.3.5 Microphone position(s)
Should more than one operator’s position be provided, measurement shall be carried out for all positions.
A.4 Operating conditions
The machine shall be equipped as determined by the manufacturer, i.e. all working units shall be fitted.
A.4.1 Fan speed
If the engine of the equipment or its hydraulic system is fitted with (a) fans(s) it (they) must operate
during the test. The fan speed is, in accordance with one of the following conditions, stated and set by the
manufacturer of the equipment and must appear in the test report, this speed being used in further
measurements.
(a) Fan drive directly connected to the engine
If the fan drive is directly connected to the engine and/or hydraulic equipment (e.g. by belt drive) it must
operate during the test.
(b) Fan drive with several distinct speeds
If the fan can work at several distinct speeds the test shall be carried out either
— at its maximum working speed, or
— in a first test with the fan set at zero speed and in a second test the fan set at maximum speed. The
resulting sound pressure level L shall then be calculated by combining both test results using the
pA
following equation:
L = 10 lg {0,3 × 100,1 L ,0 % + 0,7 × 100,1 L ,100 %}
pA pA pA
where:
ISO/DIS 20500-2:2020(E)
L ,0 % is the sound pressure level determined with the fan set at zero speed
pA
L ,100 % is the sound pressure level determined with the fan set at maximum speed.
pA
(c) Fan drive with continuous variable speed
If the fan can work at continuous variable speed, the test shall be carried out either according to 2.1(b)
or with the fan speed set by the manufacturer at no less than 70 % of the maximum speed.
A.4.2 Operating conditions for working units
The engine of the machine shall operate at the nominal speed indicated by the manufacturer. All working
units (e.g. milling equipment, conveyor, EVAC-ERD) shall be activated and operate at their respective
rated speeds free of load.
A.5 Uncertainty
The measurement uncertainty and, in the case of series machines, the uncertainty due to production
variations shall be considered when determining the value of the A-weighted sound power level and that
of the A-weighted emission sound pressure level at the operator's position.
Current experience shows that the total uncertainty (measurement plus production) of road-milling
machines is less than K = 1,0 dB for the A-weighted sound power levels and less than K = 2,0 dB for
WA pA
the A-weighted emission sound pressure level.
A.6 Information to be recorded
ISO 3744 and ISO 11201 shall apply with the following additions:
— type and output of engine;
— engine speed;
— fan speed;
— measurement duration t for each measurement;
M
— description of the test environment;
— A-weighted sound power level from each of the three measurements and the resulting sound power
level as emission value;
— A-weighted sound pressure levels from each of the three measurements at the operator's position
and the resulting emission sound pressure level;
— place, date of measurement, test laboratory and person responsible.
A.7 Informatio
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