Mechanical vibration - Hand-held and hand-guided machinery - Principles for evaluation of vibration emission (ISO 20643:2005)

This document provides the basis for the drafting of vibration test codes for hand-held and hand-guided power-driven machinery. It specifies the determination of hand-transmitted vibration emission in terms of frequency-weighted root-mean-square (r.m.s.) acceleration during type testing. For machines where vibration test codes do not exist, it may also be used for determination of emission values and contains sufficient guidance for designing an appropriate test.
NOTE   Vibration test codes based on this document should define measuring procedures which provide controlled, repeatable and reproducible results which are, as far as possible, in agreement with the vibration values measured at the machine-hand contact surfaces under real working conditions and for which the uncertainties of measurement are quantified.
This document is applicable to hand-held power tools (e.g. chipping hammers, sanders), hand-guided powered machines (e.g. lawn mowers, single-axle tractors, vibratory rollers) and other types of powered machines fitted with handles, guiding beams or similar means of control. It is applicable to machinery of all power sources (electrical, hydraulic, pneumatic, internal combustion engine, etc.).
It does not apply to fixed machinery in which the vibration is transmitted to the hands of the user through the workpiece.
This document is not applicable to vibration transmitted from steering wheels or control levers of mobile machinery where the operator's position is on the machine, see EN 1032.
It is restricted to translational vibration measured in three orthogonal directions at the hand-machine interface.
This document should be applied with caution to machines producing single and repetitive shocks with a frequency of occurrence lower than 5 Hz. For such machines, it is not known whether frequency-weighted root-mean-square acceleration values are related to the risks to health and additional measurements may be required. When developing vibration test code

Mechanische Schwingungen - Handgehaltene und handgeführte Maschinen - Grundsätzliches Vorgehen bei der Ermittlung der Schwingungsemission (ISO 20643:2005)

5
Dieses Dokument stellt die Grundlage für die Erstellung von Schwingungsmessnormen für handgehaltene und
handgeführte kraftbetriebene Maschinen dar. Es legt die Ermittlung der Hand-Arm-Schwingungen, angegeben
als Effektivwert der frequenzbewerteten Beschleunigung, während der Typprüfung (Messung von Maschinen-
kennwerten)  fest.  Es  kann  auch  zur  Ermittlung  der  Schwingungsemissionswerte  (Schwingungskennwerte)
solcher Maschinen herangezogen werden, für die keine Schwingungsmessnormen vorliegen, und stellt eine
hinreichende Anleitung zur Gestaltung einer geeigneten Prüfung dar.
ANMERKUNG Schwingungsmessnormen, die auf diesem Dokument beruhen,  sollten  Verfahren  zur  Ermittlung  von
Maschinenkennwerten festlegen, welche wiederholbare und vergleichbare Ergebnisse unter kontrollierten Bedingungen
liefern, die so weit wie möglich in Übereinstimmung mit den Schwingungswerten an den Kontaktflächen zwischen Hand
und Maschine sind, die unter realen  Arbeitsbedingungen  gemessen  werden,  und  deren  Messunsicherheit  quantifiziert
wird.
Dieses Dokument gilt für handgehaltene Maschinen (z. B. Meißelhammer, Schwingschleifer), handgeführte
Maschinen (z. B. Rasenmäher, Einachs-Traktor, Rüttelwalze) und andere Maschinenarten zu ermitteln,  die
mit Griffen, Holmen oder ähnlichen Lenkvorrichtungen versehen sind. Es gilt für motorbetriebene Maschinen,
die  sich  aus  beliebiger  Fremdenergie  speisen  (elektrisch,  hydraulisch,  pneumatisch,  Verbrennungsmotor
usw.).
Es gilt nicht für stationäre Maschinen, bei denen die Schwingungen über das Werkstück auf die Hände der
Bedienungsperson (des Beschäftigten) übertragen werden.
Dieses  Dokument  ist  nicht  auf  die  Schwingungen  anwendbar,  die  von  Lenkrädern  oder  Steuerhebeln
(Stellteilen) beweglicher Maschinen ausgehen, bei denen sich der Arbeitsplatz der Bedienungsperson auf der
Maschine befindet (siehe EN 1032).

Vibration mécanique - Machines tenues et guidées a la main - Principes pour l'évaluation d'émission de vibrations (ISO 20643:2005)

Le présent document fournit la base pour l'élaboration des codes d'essai de vibrations pour les machines a moteur tenues a la main et guidées a la main. Elle spécifie la détermination de l'émission vibratoire en terme de moyenne quadratique (r.m.s) d'accélération pondérée en fréquence pendant l'essai de type. Pour les machines ou le code d'essai de vibration n'existe pas, elle peut etre utilisée également pour la détermination de valeurs d'émission et comporte suffisamment d'informations pour la mise en place d'un essai.
NOTE   Il est recommandé que les codes d'essai de vibrations basés sur le présent document définissent les modes opératoires de mesurage conduisant a des résultats précis, répétables et reproductibles qui soient, autant que possible, en accord avec les valeurs de vibrations mesurées au niveau des surfaces de contact entre la machine et la main sous des conditions réelles de travail et pour lesquels les incertitudes de mesure sont évaluées quantitativement.
Le présent document est applicable aux machines a moteur portatives (par exemple marteaux burineurs, ponceuses), aux machines a moteur guidées a la main (par exemple tondeuses a gazon, tracteurs a essieu unique, compacteurs vibrants) et aux autres types de machines a moteur munies de poignées, de manches de guidage ou d'autres moyens de commande similaires. Elle est applicable aux machines fonctionnant avec tout type de puissance non manuelle (électrique, hydraulique, pneumatique, moteur a combustion interne, etc.).
Elle ne s'applique pas aux machines fixes pour lesquelles les vibrations sont transmises aux mains de l'opérateur via la piece.
Le présent document ne s'applique pas aux vibrations transmises par les volants de direction ou les leviers de commande des machines mobiles quand la position de l'opérateur est sur la machine, voir l'EN 1032.

Mehanične vibracije – Prenosni ročni in ročno vodeni stroji – Načela vrednotenja oddajanja vibracij (ISO 20643:2005)

General Information

Status
Withdrawn
Publication Date
30-Apr-2005
Withdrawal Date
27-Aug-2008
Technical Committee
Current Stage
9900 - Withdrawal (Adopted Project)
Start Date
26-Aug-2008
Due Date
18-Sep-2008
Completion Date
28-Aug-2008

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SLOVENSKI STANDARD
SIST EN ISO 20643:2005
01-maj-2005
1DGRPHãþD
SIST EN 1033:2000
0HKDQLþQHYLEUDFLMH±3UHQRVQLURþQLLQURþQRYRGHQLVWURML±1DþHODYUHGQRWHQMD
RGGDMDQMDYLEUDFLM ,62
Mechanical vibration - Hand-held and hand-guided machinery - Principles for evaluation
of vibration emission (ISO 20643:2005)
Mechanische Schwingungen - Handgehaltene und handgeführte Maschinen -
Grundsätzliches Vorgehen bei der Ermittlung der Schwingungsemission (ISO
20643:2005)
Vibration mécanique - Machines tenues et guidées a la main - Principes pour l'évaluation
d'émission de vibrations (ISO 20643:2005)
Ta slovenski standard je istoveten z: EN ISO 20643:2005
ICS:
13.160 Vpliv vibracij in udarcev na Vibration and shock with
ljudi respect to human beings
25.140.01 5RþQDRURGMDQDVSORãQR Hand-held tools in general
SIST EN ISO 20643:2005 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN ISO 20643:2005

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SIST EN ISO 20643:2005



EUROPEAN STANDARD
EN ISO 20643

NORME EUROPÉENNE

EUROPÄISCHE NORM
January 2005
ICS 13.160 Supersedes EN 1033:1995
English version
Mechanical vibration - Hand-held and hand-guided machinery -
Principles for evaluation of vibration emission (ISO 20643:2005)
Vibration mécanique - Machines tenues et guidées à la Mechanische Schwingungen - Handgehaltene und
main - Evaluation d'émission de vibration (ISO handgeführte Maschinen - Grundsätzliches Vorgehen bei
20643:2005) der Ermittlung der Schwingungsemission (ISO 20643:2005)
This European Standard was approved by CEN on 30 September 2004.

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

This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official
versions.

CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,
Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia,
Slovenia, Spain, Sweden, Switzerland and United Kingdom.




EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2005 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 20643:2005: E
worldwide for CEN national Members.

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EN ISO 20643:2005 (E)
Contents
page
Foreword.3
1 Scope .6
2 Normative references.7
3 Terms, definitions and symbols.7
3.1 Terms and definitions .7
3.2 Symbols.8
4 Basic standards and vibration test codes .9
5 Description of a family of machines.9
6 Characterization of vibration.9
6.1 Direction of measurement .9
6.2 Location of measurement.10
6.3 Magnitude of vibration .11
6.4 Combination of vibration directions.11
7 Instrumentation requirements.12
7.1 General .12
7.2 Mounting of transducers .12
7.2.1 Specification of transducer .12
7.2.2 Fastening of transducer.12
7.3 Frequency weighting filter.12
7.4 Integration time.12
7.5 Auxiliary equipment .12
7.6 Calibration of the measurement chain .13
8 Testing and operating conditions of the machinery.13
8.1 General .13
8.2 Operating conditions.13
8.3 Other quantities to be specified.13
8.4 Attached equipment, workpiece and task.13
8.5 Operator.14
9 Measurement procedure and validity.14
9.1 Reported vibration value .14
9.2 Declaration and verification of the vibration emission value .14
10 Measurement report .14
Annex A (normative)  Summary of information to be given in the vibration test code.16
Annex B (informative)  Possible sources of errors during vibration measurements.18
Annex C (normative)  Procedure for developing a vibration test code for a specific category of hand-
held or hand-guided machinery.19
Annex ZA (informative)  Relationship between this European Standard and the Essential
Requirements of EU Directive 98/37/EC.20
Bibliography .21



2

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Foreword
This document (EN ISO 20643:2005) has been prepared by Technical Committee CEN/TC 231 "Mechanical
vibration and shock", the secretariat of which is held by DIN, in collaboration with Technical Committee ISO/TC 118
"Compressors, pneumatic tools and pneumatic machines".
This European Standard shall be given the status of a national standard, either by publication of an identical text or
by endorsement, at the latest by July 2005, and conflicting national standards shall be withdrawn at the latest by
July 2005.
This document supersedes EN 1033:1995.
This document has been prepared under a mandate given to CEN by the European Commission and the European
Free Trade Association, and supports essential requirements of EC Directive(s).
For relationship with EC Directive(s), see informative Annex ZA, which is an integral part of this document.
This document provides concrete rules for the application of EN 12786 in relation to vibration test codes. It is
complementary to EN 12096.
New or revised vibration test codes in the standards series EN 28662/EN ISO 8662 for portable hand-held
machines will be based on this document. All currently existing parts of EN 28662/EN ISO 8662, however, are
based on EN 28662-1:1993. It is envisaged that EN 28662-1:1993 will be withdrawn when all parts of the series
EN 28662/EN ISO 8662 have been revised in accordance with this document.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic, Denmark,
Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
3

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Introduction
Human exposure to mechanical vibration from hand-held or hand-guided machinery can interfere with comfort,
working efficiency and, in some circumstances, health and safety. According to EN ISO 12100-2 the risks created
by vibrating machinery need to be minimized and the residual risk from vibration need to be noted in the relevant
instruction handbook. This, ideally, will be based on the vibration emission magnitude reported in accordance with
this document or the relevant vibration test code, but additional information for use may be required (see Clause 6
in EN ISO 12100-2:2003).
It is possible that the type test method may not identify all the mechanisms that generate vibration when the
machine is used in the real operational environment. Factors such as the workpiece, the process and the operator
can have an important influence on the vibration magnitudes. For this reason the type test measurements cannot
replace field measurements to evaluate vibration exposure at the workplace, but should be sufficiently
representative to be able to be used for preliminary assessment of risk.
Vibration magnitudes in type tests shall be within the range of measurements made in the field, but with less
variability. Type tests require accurate and reproducible conditions. It is essential that different laboratories obtain
the same results within specified limits. This requires that the process or way in which the machine is measured is
precisely defined. The operating conditions should be well defined, they should preferably be a real process, typical
of that for which the machine is designed. If it is intended to be used for a variety of tasks and the vibration is
affected significantly by the task, then more than one task might be used in determination of vibration emission. In
some cases an artificial process may be used which is not in line with the typical use of the machine in the field but
which provides equivalent data. If two machines produce significantly different magnitudes of vibration under real
conditions, then the test should be capable of demonstrating this difference.
This document is intended to assist technical standardization committees responsible for specific types of
machinery in preparing vibration test codes to ensure that such vibration test codes:
— enable users to make comparisons and to check the declared vibration emission values;
— are as homogeneous as possible with each individual test code having the same basic structure;
— are in full accordance with basic type-B standards on measurement of vibration emissions;
— reflect the latest technical knowledge of methods of determining the vibration emissions from the specific
family of machinery under consideration.
A vibration test code for a family of machinery prepared in accordance with this document:
a) produces vibration emission data which allow the determination of the vibration state-of-the-art for a family of
machinery and the identification of a machine which has significantly greater or smaller vibration emission;
b) produces vibration emission values and uncertainties suitable for comparing the emissions of machinery of the
same type irrespective of the date or location of the testing;
c) produces vibration emission values and uncertainties corresponding to the upper quartile of vibration
magnitudes resulting from intended uses of the machinery;
d) specifies the operating conditions of the machine during testing that are, so far as practicable, representative of
normal use;
e) identifies parameters that have a significant influence on the vibration emission of the machinery;
f) specifies installation and mounting conditions of transducers, measurement positions and measurement
directions;
4

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EN ISO 20643:2005 (E)
g) prescribes equipment used during testing and
h) requires recording of the values of machinery operating parameters that may influence vibration emission.
This document can be used, in the absence of an agreed vibration test code, as a guide to determine vibration
emission values and to define test parameters that may influence vibration emission to be recorded.
This document is a type-B standard as stated in EN ISO 12100-1.
The provisions of this document may be supplemented or modified by a type-C standard. However, for machines
which are covered by the scope of a type-C standard and which have been designed and built according to the provisions of
that standard, the provisions of that type-C standard take precedence over the provisions of this type-B standard.
5

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EN ISO 20643:2005 (E)

1 Scope
This document provides the basis for the drafting of vibration test codes for hand-held and hand-guided power-
driven machinery. It specifies the determination of hand-transmitted vibration emission in terms of frequency-
weighted root-mean-square (r.m.s.) acceleration during type testing. For machines where vibration test codes do
not exist, it may also be used for determination of emission values and contains sufficient guidance for designing
an appropriate test.
NOTE Vibration test codes based on this document should define measuring procedures which provide controlled,
repeatable and reproducible results which are, as far as possible, in agreement with the vibration values measured at the
machine-hand contact surfaces under real working conditions and for which the uncertainties of measurement are quantified.
This document is applicable to hand-held power tools (e.g. chipping hammers, sanders), hand-guided powered
machines (e.g. lawn mowers, single-axle tractors, vibratory rollers) and other types of powered machines fitted with
handles, guiding beams or similar means of control. It is applicable to machinery of all power sources (electrical,
hydraulic, pneumatic, internal combustion engine, etc.).
It does not apply to fixed machinery in which the vibration is transmitted to the hands of the user through the
workpiece.
This document is not applicable to vibration transmitted from steering wheels or control levers of mobile machinery
where the operator's position is on the machine, see EN 1032.
It is restricted to translational vibration measured in three orthogonal directions at the hand-machine interface.
This document should be applied with caution to machines producing single and repetitive shocks with a frequency
of occurrence lower than 5 Hz. For such machines, it is not known whether frequency-weighted root-mean-square
acceleration values are related to the risks to health and additional measurements may be required. When
developing vibration test codes for such machines the information in CEN ISO/TS 15694 should be considered.
This document is not applicable to vibration test codes published before the date of publication of this document by
CEN and, when used as test code, to hand-held and hand-guided machinery manufactured before that date.
This document does not present limits or recommended vibration values. It does not give any guidance or
recommendations for determination of human exposure to vibration at the workplace. For such information,
reference is made to EN ISO 5349-1 and EN ISO 5349-2.
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2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references,
only the edition cited applies. For undated references, the latest edition of the referenced document (including any
amendments) applies.
EN 12096, Mechanical vibration — Declaration and verification of vibration emission values.
ENV 28041, Human response to vibration — Measuring instrumentation (ISO 8041:1990).
EN ISO 5349-1, Mechanical vibration — Measurement and evaluation of human exposure to hand-transmitted
vibration — Part 1: General requirements (ISO 5349-1:2001).
ISO 2041:1990, Vibration and shock — Vocabulary.
ISO 5347 (all parts), Methods for the calibration of vibration and shock pick-ups.
ISO 5805:1997, Mechanical vibration and shock — Human exposure — Vocabulary.
ISO 16063 (all parts), Methods for the calibration of vibration and shock transducers.
3 Terms, definitions and symbols
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 2041:1990 and ISO 5805:1997 and the
following apply.
3.1.1
family of machinery
machines of similar design to fulfil the same functions
EXAMPLE chain saws
3.1.2
hand-guided machine
machine which is guided by the operator with his hands, such that the vibration exposure is obtained through the
handles, steering wheel or tiller
[EN ISO 5349-2]
EXAMPLE walk-behind cutting machine, swing grinder
3.1.3
hand-held power tool
powered tool which is held in the hand and for which a feed force is necessary to fulfil a task
EXAMPLE electric drill, pneumatic chisel, chain-saw
3.1.4
inserted tool
interchangeable or replaceable attachment which fits into or onto a hand-held power tool or hand-guided machine
for performing the intended operation
EXAMPLE drill bit, chisel, saw chain, saw blade, abrasive wheel
7

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3.1.5
equipment
specific interchangeable attachment other than an inserted tool to complete the machine
EXAMPLE guards, side handles
3.1.6
operation
identified task for which a representative vibration magnitude measurement is made; this may be for a single phase
of a task or a working cycle, that means a set of tool operations which are necessary to fulfil a task
3.1.7
operator
person using a power tool
3.1.8
tool operation
any period during which a power tool is operating and the operator is being exposed to hand-transmitted vibration
[EN ISO 5349-2]
3.1.9
workpiece
item being operated upon by a power tool
[EN ISO 5349-2]
3.2 Symbols
In this document, the following symbols are used.
a (t) instantaneous single-axis acceleration value of the frequency-weighted hand-transmitted
hw
vibration at time t, in m/s²
a root-mean-square (r.m.s.) single-axis acceleration value of the frequency-weighted hand-
hw
transmitted vibration, in m/s²
a , a , a values of a in m/s², for the axes denoted x, y and z respectively
hwx hwy hwz hw
a vibration total value of frequency-weighted r.m.s. acceleration, in m/s²; it is the root-sum-of-
hv
squares of the a values for the three measured axes of vibration
hw
a arithmetic mean value of the measurement results of runs and operators, in m/s²; this is the
h
result of the test
a declared vibration value in m/s² (the quantity denoted a in EN 12096)
hd
σ standard deviation of reproducibility
R
2
K uncertainty in m/s of a as defined in EN 12096
hd
C coefficient of variation of a test series, defined as the ratio of the standard deviation of a series
V
of measurement values and the mean value of the series:
s
N−1
C =
V
a
hw
where
8

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N
1
2
 s = (a − a ) is the standard deviation

N−1 hwi hw
N −1
i = 1
 a is the mean value of the series in m/s²
hw
 a is the i-th value measured in m/s²
hwi
 N is the number of measured values
4 Basic standards and vibration test codes
The preparation of vibration test codes for hand-held and hand-guided machinery shall be based on the
requirements of this document and, for declaration and verification, also on the requirements of EN 12096.
A vibration test code is a type-C standard relative to a specified family or sub-family or type of machinery. It shall
give all the information necessary to carry out efficiently the determination, declaration and verification of the
vibration emission characteristics. It shall ensure compatibility and allow comparison of test results. A summary of
the requirements of this document for vibration test codes is given in Annex A.
Where no specific vibration test codes exists for a family of machines, this document shall be used as a test code.
In such cases details of the measurement method and machine operation (see Clauses 6, 7 and 8) shall be fully
reported.
NOTE EN 12096 gives guidance on how to declare the vibration emission values of machinery, and specifies requirements
for verification of declared values.
5 Description of a family of machines
The family or type of machinery covered by the vibration test code shall be described unambiguously and in detail.
In describing the configuration of the machinery, a vibration test code shall:
— identify any inserted tools used in the operation of the machine under test and which may influence the
vibration emission;
— specify the selection of other equipment which may influence the vibration emission and which shall be used
during the determination of vibration emission;
— identify the range of applications for which the vibration test code is intended.
6 Characterization of vibration
6.1 Direction of measurement
Translational vibration transmitted to the hand is related to the x, y or z directions shown in Figure 1. For a family of
machinery, these directions of vibration measurement shall be defined in the vibration test code.
NOTE Other directions of vibration (e.g. rotational motion) are not dealt with in this document.
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a) "Handgrip" position
(In this position, the hand grips a cylindrical hand grip)

b) "Flat palm" position
(In this position, the hand presses down onto a spherical hand grip)
Figure 1 — Directions of vibration measurement
6.2 Location of measurement
As a basic rule, measurements shall be made simultaneously in three directions for each hand position.
If, in some cases, it is not possible to make vibration measurements in three axes, the vibration test code may
specify that measurements are made only in one or two axes, but the axis of greatest vibration shall be included
(where this can be identified).
Sequential measurement in the three directions is undesirable, and is more time consuming. However, it is
permissible where the total size or mass of three transducers prevents correct operation of the machine or is likely
to affect the measurement (see 7.2.1).
Measurements shall be carried out as close as possible to a point on the grip surface half-way along the length of
the grips or at such places where an operator normally holds the machine during a typical operation. If the placing
of the switch actuator makes this impossible then the accelerometer shall be placed as close as possible to the
hand between the thumb and the index finger.
It is possible to get differences between vibration measurements across the width of the hand position, particularly
for hand-held power tools with side handles such as angle grinders, and especially where these handles are
10

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flexibly mounted. In these cases, two accelerometer positions shall be used, located at either side of the hand
position and the mean value of the magnitudes measured at the two positions shall be calculated.
The specification of measurement positions shall be given in the vibration test code.
When machines are operated with two hand grips, the vibration at both hand positions shall be measured and
recorded. If it can be shown that the vibration magnitude at one grip is dominant the vibration test code may specify
that measurements are made only at that gripping zone. Where inserted tools must be held by the operator (e.g.
chipping hammer chisels) this is likely to be the hand position of greatest vibration and should be included in the
evaluation of vibration emission.
6.3 Magnitude of vibration
The quantity used to describe the magnitude of vibration shall be the frequency-weighted acceleration a in m/s².
hw
The frequency weighting to be used is defined in 7.3.
The r.m.s. value a in accordance with this document is defined as the r.m.s. value of the frequency-weighted
hw
acceleration signal a (t):
hw
1/ 2
T
 
1
2
a = a (t) dt          (1)
hw  hw 

T
 0 
Requirements for the integration time T are given in 7.4.
NOTE Frequency analysis is recommended in order to check the validity of the measurements and to provide additional
information.
6.4 Combination of vibration directions
The vibration total value a is determined from
hv
1/ 2
2 2 2
a =[]a + a + a         (2)
hv
hwx hwy hwz
where
a , a , a are the r.m.s. values of the frequency-weighted acceleration in the x-, y- and z-direction,
hwx hwy hwz
respectively
If measurements are not made in all three directions, the value a shall be estimated using the measured value(s)
hv
available and a carefully considered multiplying factor. The vibration magnitude in the axis of greatest vibration
requires a multiplying factor in the range 1,0 to 1,7 to give the vibration total value (for further advice,
see EN ISO 5349-2). Where a multiplying factor is used to estimate the vibration total value, it shall be justified in
the vibration test code.
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7 Instrumentation requirements
7.1 General
The vibration measurement system shall be in accordance with ENV 28041.
Instrumentation for measuring other parameters (e.g. for controlling the working conditions), whose characteristics
are not covered by ENV 28041, shall be specified in the vibration test code. The justification for use of such
instrumentation shall be given, together with a detailed specification of the instrumentation.
7.2 Mounting of transducers
7.2.1 Specification of transducer
The vibration values as specified in 6.3 shall be measured using transducers and other appropriate measurement
equipment conforming to ENV 28041.
The total mass of the vibration transducer and its mounting shall be small enough, compared with that of the tool,
handle, etc., on which it is mounted, not to influence the measurement result.
NOTE This is particularly important for light-weight plastic handles (see EN ISO 5349-2 for further information).
Factors such as the transverse sensitivity (less than 10 %), the ambient temperature range, the typical temperature
transient sensitivity and the max
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