ISO 22868:2021

INTERNATIONAL ISO
STANDARD 22868
Third edition
2021-01
Forestry and gardening machinery —
Noise test code for portable hand-
held machines with internal
combustion engine — Engineering
method (Grade 2 accuracy)
Machines forestières et machines de jardin — Code d'essai
acoustique pour machines portatives tenues à la main à moteur à
combustion interne — Méthode d'expertise (classe de précision 2)
Reference number
ISO 22868:2021(E)
©
ISO 2021

---------------------- Page: 1 ----------------------
ISO 22868:2021(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2021
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2021 – All rights reserved

---------------------- Page: 2 ----------------------
ISO 22868:2021(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Quantities to be measured and quantities to be determined . 2
5 A-weighted sound power level determination . 2
6 A-weighted emission sound pressure level measurement at the operator position .4
6.1 General . 4
6.2 Requirements for artificial surface . 4
6.3 Requirements for natural ground surface . 5
7 Testing and operating conditions . 5
8 Information to be reported . 6
8.1 General . 6
8.2 A-weighted emission sound pressure level determination . 7
8.3 A-weighted surface average sound pressure level determination . 7
8.4 A-weighted sound power level determination . 8
9 Declaration and verification of noise emission values . 9
Annex A (normative) Specific conditions for chain-saws (see Clause 7) .10
Annex B (normative) Specific conditions for brush-cutters, grass-trimmers and edgers
(see Clause 7) .14
Annex C (normative) Specific conditions for pole-mounted powered pruners (see Clause 7).20
Annex D (normative) Specific conditions for hedge-trimmers (see Clause 7) .24
Annex E (normative) Specific conditions for garden blowers/vacuums/knapsack mist
blowers (see Clause 7) .28
Annex F (informative) Example of water brake mounted on chain-saw guide bar to simulate
cutting .35
Annex G (informative) Summary of results from round robin tests 2007 and 2008 on single
chain-saw, brush-cutter and grass-trimmer .36
Annex H (informative) A-weighted sound power level determination and declaration
according to the EU Directive on noise emission in the environment by equipment
for use outdoors, 2000/14/EC .37
© ISO 2021 – All rights reserved iii

---------------------- Page: 3 ----------------------
ISO 22868:2021(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 23, Tractors and machinery for agriculture
and forestry, Subcommittee SC 17, Manually portable forest machinery, in collaboration with the European
Committee for Standardization (CEN) Technical Committee CEN/TC 144, Tractors and machinery for
agriculture and forestry, in accordance with the Agreement on technical cooperation between ISO and
CEN (Vienna Agreement).
This third edition cancels and replaces the second edition (ISO 22868:2011), which has been technically
revised. The main changes compared to the previous edition are as follows:
— inclusion of edgers and knapsack mist blowers in the scope;
— correction of the calculation of microphone positions for the hemisphere (Figure 1) according to
ISO 3744:2010;
— alignment of the operation conditions for the determination of the sound power level with those for
the determination of the emission sound pressure level;
— lateral width of the test timber for chain-saw testing reduced to 150 mm to account for small
machines with short guide bars;
— inclusion of edgers in the specific conditions described in Annex B;
— amendments in Annex E to include knapsack mist blowers and better describe the set-up of the
machines with different blower tubes;
— editorial corrections and update of all figures as well as addition of new figures for edgers and mist
blowers;
— several text changes have been made for better understanding.
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.
iv © ISO 2021 – All rights reserved

---------------------- Page: 4 ----------------------
ISO 22868:2021(E)

Introduction
This document is a type-C standard as stated in ISO 12100.
This document is of relevance, in particular, for the following stakeholder groups representing the
market players with regard to machinery safety:
— machine manufacturers (small, medium and large enterprises);
— health and safety bodies (regulators, accident prevention organisations, market surveillance, etc.)
Others can be affected by the level of machinery safety achieved with the means of the document by the
above-mentioned stakeholder groups:
— machine users/employers (small, medium and large enterprises);
— machine users/employees (e.g. trade unions, organizations for people with special needs);
— service providers, e.g. for maintenance (small, medium and large enterprises);
— consumers (in case of machinery intended for use by consumers).
The above-mentioned stakeholder groups have been given the possibility to participate at the drafting
process of this document.
The machinery concerned and the extent to which hazards, hazardous situations or hazardous events
are covered are indicated in the Scope of this document.
When requirements of this type-C standard are different from those which are stated in type-A or B
standards, the requirements of this type-C standard take precedence over the requirements of the
other standards for machines that have been designed and built according to the requirements of this
type-C standard.
During the first steps in the preparation of this document, it became obvious that the repeatability
of the test results could become better if the operator were to be replaced by a simulation process,
representing the normal operating modes with chain-saws and grass-trimmers/brush-cutters.
Furthermore, it was found that the cutting process performed with chain-saws causes considerable
deviations, which are not related to the measured object but to the test procedure itself.
Based on these observations, it was concluded that the operators in both test procedures, i.e. for chain-
saws and grass-trimmers/brush-cutters, ought to be replaced by a defined fixture and the cutting
process with chain-saws by a brake simulating the load. In this manner, the operating conditions during
measurement would simulate normal operating conditions.
The determination of noise emission characteristics is primarily intended for
— the manufacturers' declarations of noise emitted,
— comparing the noise emitted by machines in the family concerned, and
— purposes of noise control at source at the design stage.
The use of this noise test code will ensure 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 document give results with
Grade 2 accuracy.
The operating modes specified for the tests are consistent with those involved in the assessment of the
exposure sound pressure levels, for example, over a typical working day.
NOTE Exposure sound pressure levels are the mean sound pressure levels experienced by the operator over
a defined period of time.
© ISO 2021 – All rights reserved v

---------------------- Page: 5 ----------------------
ISO 22868:2021(E)

The work cycles chosen for this test code are based on the following considerations of application:
3
a) chain-saws with an engine of < 80 cm are used for various operations, including felling, bucking
and delimbing;
3
b) chain-saws with an engine of ≥ 80 cm are normally used for felling and bucking.
Delimbing will cause the chain-saw to run at racing speed; therefore, racing is included only for chain-
3
saws with a < 80 cm engine.
For brush-cutters, grass-trimmers, edgers, hedge-trimmers and pole-mounted powered pruners, the
cutting mode (full load) is estimated to be valid only for short periods, while racing and idling are the
two dominant modes. Moreover, it has also been found to be diverse and not able to be performed under
repeatable conditions.
For grass-trimmers, the full load and the racing modes are integrated in one single mode due to the
loading effect of the flexible line.
For brush-cutters, edgers, hedge-trimmers and pole-mounted powered pruners, it is not possible to
simulate the full load mode in a feasible way since there are no constant load conditions comparable
to chain-saws. Since the operating mode “racing” is anyhow the worst case, it is used as representative.
For garden blowers and knapsack mist blowers, full load and idling are the two dominant modes.
In either case, transport and other tasks between operations will cause the machine to run at idling.
Experience has led to the conclusion that, except for hedge-trimmers and blowers/knapsack mist
blowers, equal duration for the different working modes is a good estimation of daily exposure.
For hedge-trimmers, experience has shown that the machine is used 1/5 at idling and 4/5 at racing,
while for garden blowers/knapsack mist blowers it is used 1/7 at idling and 6/7 at racing.
A summary of results from “round-robin” tests, carried out between 2007 and 2008 in up to eight test
laboratories on a single chain-saw, brush-cutter and grass-trimmer, is given in Annex G.
vi © ISO 2021 – All rights reserved

---------------------- Page: 6 ----------------------
INTERNATIONAL STANDARD ISO 22868:2021(E)
Forestry and gardening machinery — Noise test code for
portable hand-held machines with internal combustion
engine — Engineering method (Grade 2 accuracy)
CAUTION — Some of the test procedures specified in this document involve processes which
could lead to a hazardous situation. Any person performing tests in accordance with this
document shall be appropriately trained in the type of work to be carried out.
1 Scope
This document specifies a noise test code for determining, efficiently and under standardized
conditions, the common noise emission characteristics of portable, hand-held, combustion engine
powered forest and garden machines, and specific requirements for chain-saws, brush-cutters, grass-
trimmers, edgers, pole-mounted powered pruners, hedge-trimmers and garden blowers/vacuums/
knapsack mist blowers. Noise emission characteristics include the A-weighted emission sound pressure
level at the operator position and the A-weighted sound power level.
Noise test codes as described in this document enable the manufacturer to verify the effort regarding
low noise design.
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 354:2003, Acoustics — Measurement of sound absorption in a reverberation room
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 4871:1996, Acoustics — Declaration and verification of noise emission values of machinery and
equipment
ISO 6531:2017, Machinery for forestry — Portable chain-saws — Vocabulary
ISO 7112:2018, Machinery for forestry — Portable brush-cutters and grass-trimmers — Vocabulary
ISO 7293:1997, Forestry machinery — Portable chain saws — Engine performance and fuel consumption
ISO 8893:1997, Forestry machinery — Portable brush-cutters and grass-trimmers — Engine performance
and fuel consumption
ISO 10517:2019, Powered hand-held hedge trimmers — Safety
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 11680-1:2011, Machinery for forestry — Safety requirements and testing for pole-mounted powered
pruners — Part 1: Machines fitted with an integral combustion engine
ISO 11680-2:2011, Machinery for forestry — Safety requirements and testing for pole-mounted powered
pruners — Part 2: Machines for use with back-pack power source
© ISO 2021 – All rights reserved 1

---------------------- Page: 7 ----------------------
ISO 22868:2021(E)

ISO 11789:1999, Powered edgers with rigid cutting means — Definitions, safety requirements and test
procedures
ISO 12100:2010, Safety of machinery — General principles for design — Risk assessment and risk reduction
ISO 19932-1:2013, Equipment for crop protection — Knapsack sprayers — Part 1: Safety and environmental
requirements
ISO 28139:2019, Agricultural and forestry machinery — Knapsack combustion-engine-driven airblast
sprayers — Safety and environmental requirements and test methods
IEC 61672-1:2013, Electroacoustics — Sound level meters — Part 1: Specifications
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 12100, ISO 6531, ISO 7112,
ISO 11789, ISO 11680-1, ISO 11680-2, ISO 10517, ISO 19932-1 and ISO 28139 apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
4 Quantities to be measured and quantities to be determined
The quantities to be measured are the time averaged sound pressure levels defined in the relevant basic
noise measurement standards (ISO 3744, ISO 11201), A-weighted and — if required — in frequency bands.
The quantities to be determined are the sound power levels and the emission sound pressure levels,
A-weighted and — if required — in frequency bands.
5 A-weighted sound power level determination
For the determination of the A-weighted sound power level, ISO 3744 shall be used, subject to the
following modifications or additions.
a) The microphone array shall be six microphone positions, in accordance with Figure 1 and the
coordinates described by Tables 1 and 2.
NOTE 1 The six microphone array is permitted because experimental data have shown that use of this
array does not yield results that differ significantly from those obtained with the 10 microphone array
specified in ISO 3744.
b) The measurement surface shall be a hemisphere with a radius, r, of ≥ 2 d , preferably 4 m; d is
O O
determined by the reference box and its defined location above ground, see Figure 1. If a bigger
radius is needed it shall be chosen from 6 m, 8 m and 10 m. A smaller radius is permitted if it is
demonstrated that the results are within 0,5 dB compared with measurements with a hemisphere
of r = 4 m.
NOTE 2 The smaller radius can be necessary in an anechoic room where a radius of 4 m cannot be
provided.
c) The conditions for the particular type of machine to be tested and its mounting and orientation
shall be according to the corresponding annex of this document.
d) Environmental conditions shall be within the limits specified by the manufacturer of the measuring
equipment. The ambient air temperature shall be in the range −10 °C to 30 °C and the wind speed
shall be less than 5 m/s. A microphone windscreen shall be used for all outdoor testing, and for
indoor testing whenever the speed of ventilation air over the microphone exceeds 1 m/s.
2 © ISO 2021 – All rights reserved

---------------------- Page: 8 ----------------------
ISO 22868:2021(E)

e) Measurements shall be made using an integrating averaging sound level meter as defined in
IEC 61672-1; alternatively, instruments with the time weighting characteristics “slow”, as defined
in IEC 61672-1, may be used.
f) The value of K , determined in accordance with ISO 3744:2010, Annex A, shall at maximum be
2A
2 dB, in which case K shall be disregarded.
2A
Key
A reference box
characteristic source dimension
d
O
r
hemisphere radius ≥ 2d
O
1 to 6 microphone positions
Figure 1 — Microphone positions on hemisphere
Table 1 — Coordinates of microphone positions
Microphone Coordinates
position No.
a a
x/r y/r z/r z
(Figure 1)
1 +0,707 a +0,707 a — 1,5 m
2 −0,707 a +0,707 a — 1,5 m
3 −0,707 a −0,707 a — 1,5 m
4 +0,707 a −0,707 a — 1,5 m
5 −0,27 +0,65 0,71 —
6 +0,27 −0,65 0,71 —
a
The constant a depends on the hemisphere radius and is taken from Table 2.
Table 2 — Values of the constant, a
r [m] a
4 0,927
6 0,968
© ISO 2021 – All rights reserved 3

---------------------- Page: 9 ----------------------
ISO 22868:2021(E)

Table 2 (continued)
r [m] a
8 0,982
10 0,989
If a non-preferred hemisphere radius is used, microphone positions 1 to 4 shall be maintained at a
height z of 1,5 m and the value of a shall be determined by Formula (1):
r²,−15²
a= (1)
r
6 A-weighted emission sound pressure level measurement at the operator
position
6.1 General
For the measurement of the A-weighted emission sound pressure level, ISO 11201 shall be used, subject
to the following modifications and additions.
a) The conditions for the particular type of machine to be tested and its mounting shall be in
accordance with the corresponding annex of this document.
b) The ground surface shall comply with the provisions of either 6.2 or 6.3. Reproducibility of results
using natural grass or other organic material is likely to be worse than that required for Grade 2 of
accuracy. In case of dispute, measurements shall be carried out in the open air and on the artificial
surface (see 6.2).
c) Environmental conditions shall be within the limits specified for the measuring equipment. The
ambient air temperature shall be in the range −10 °C to 30 °C, and the wind speed shall be less
than 5 m/s. A microphone windscreen shall be used for all outdoor testing, and for indoor testing
whenever the speed of ventilation air over the microphone exceeds 1 m/s.
d) Measurements shall be made using an integrating averaging sound level meter as defined in
IEC 61672-1; alternatively, instruments with the time weighting characteristics “slow”, as defined
in IEC 61672-1, may be used.
e) The location of a particular type of machinery respective to the microphone array shall be in
accordance with the corresponding annex of this document.
6.2 Requirements for artificial surface
The artificial surface shall have absorption coefficients in accordance with Table 3, measured according
to ISO 354.
Table 3 — Absorption coefficients
Frequencies Absorption coefficients Tolerance
Hz
125 0,1 ±0,1
250 0,3 ±0,1
500 0,5 ±0,1
1 000 0,7 ±0,1
2 000 0,8 ±0,1
4 000 0,9 ±0,1
4 © ISO 2021 – All rights reserved

---------------------- Page: 10 ----------------------
ISO 22868:2021(E)

The artificial surface shall be placed on a hard, reflecting surface at the centre of the test environment
and shall have a size of at least 3,6 m × 3,6 m. The construction of the supporting structure shall be
such that the requirements for acoustic properties are met with the absorbing material in place. The
structure shall support the test set up such that compression of the absorbing material is avoided.
6.3 Requirements for natural ground surface
The ground at the centre of the test site shall be flat and have good sound absorbing properties. The
surface shall be either forest ground or grass, with the grass or other organic material having a height
of (50 ± 20) mm.
7 Testing and operating conditions
Measurements shall be carried out on a new, normal production machine fitted with standard
equipment in accordance with the instruction handbook.
The engine and the machine shall be run in prior to the test in accordance with the manufacturer's
instructions. The engine shall be at normal stable operating temperature before the test is started.
The carburettor shall be set to give the specific machine conditions required by the corresponding
annex of this document.
The cutting devices shall be lubricated in accordance with the instruction handbook. No alterations to
the initial settings are permitted once measurements have commenced.
An engine speed indicator shall be used to check the speed of the engine. It shall have a measurement
accuracy of ± 1,0 % of the reading. The indicator and its engagement with the machine shall not affect
the operation during testing.
NOTE The specific conditions for a particular machine are given in the corresponding Annexes A to E.
Noise emission quantities shall be determined under the specific conditions for the particular type of
machine specified in the corresponding annex (i.e. Annexes A to E). The following additionally applies.
a) Perform a minimum of four measurements with a short break and significant change of speed
between each measurement. Separate each measurement at, for example, idle, by a short period of
racing, and vice versa. After this speed variation, stable speed conditions shall be obtained before
testing is continued.
At least four separate periods of noise data shall be obtained, totalling at least 20 s.
The signal duration of each measurement period shall be at least 2 s over which the engine speed is
within ± 3,5 r/s.
The collection of data for the different operating modes need not be carried out in any fixed
sequence.
b) The range of all values noted for each operating mode shall not be greater than 2 dB. If this range
is exceeded, repeat the tests until four consecutive results fall within a range of 2 dB. The final
value to be retained for each microphone position is the arithmetical mean of these four successive
values satisfying this requirement.
For all the conditions specified in the annexes, carry out this procedure when measuring the A-weighted
emission sound pressure levels. When determining the A-weighted sound power level, this procedure
shall be applied to the sound pressure levels averaged over the six microphone positions.
© ISO 2021 – All rights reserved 5

---------------------- Page: 11 ----------------------
ISO 22868:2021(E)

8 Information to be reported
8.1 General
The following information, as applicable, shall be recorded and reported for all measurements:
a) machine under test:
1) description of the machine (including its engine displacement, manufacturer, type and serial
number, and configuration of attachments);
2) operating conditions, as listed in Tables 4 and 5, during acoustical evaluation;
3) dimensions of the test timber (when applicable);
b) acoustic environment (description of test environment):
1) if outdoors, a sketch showing the location of the machine with respect to the surrounding
terrain, including a physical description of the test environment including a description of the
nature of the ground surface;
2) if indoors, a description of the physical treatment of walls, ceiling and floor, including a sketch
showing the location of the machine and room contents;
3) value of K ;
2A
c) instrumentation:
1) equipment used for the measurements, including name, type, serial number and manufacturer;
2) method used to calibrate the instrumentation system;
3) date and place of the most recent calibration of the acoustical calibrator;
d) acoustical and other data:
1) A-weighted sound pressure levels of the background noise at the microphone positions;
2) measured values and mean values in accordance with Tables 4, 5 and 6;
3) remarks, if any;
4) air temperature and wind speed;
5) date and place of the measurements.
6 © ISO 2021 – All rights reserved

---------------------- Page: 12 ----------------------
ISO 22868:2021(E)

8.2 A-weighted emission sound pressure level determination
Table 4 — A-weighted emission sound pressure level determination —
Reporting measured values, mean values and emis
...