Mechanical vibration - Guideline for the assessment of exposure to hand-transmitted vibration using available information including that provided by manufacturers of machinery
This Technical Report provides information on how to assess the vibration exposure from hand-held power tools and hand-guided machines. The methods described use existing vibration emission values declared for the machine of interest or information coming from other sources. It should be noted that vibration usually varies a lot over time, with different workstations and different operators. It is therefore not possible to get precise exposure figures from limited investigations. But also the declared values need to be used with great care since they are measured for a limited number of defined work situations. The actual work situation for a specific operator, however, may be very different thus creating different vibration. On the other hand values from real work that can be found in literature are only correct for the specific work situation and time when they were measured. The user of this Technical Report should be aware that the exposure to vibration does not only depend on the machine used but also to a large extent on things like quality of inserted tools, the work situation and operator behaviour. These factors need to be taken into account to make an ideal assessment of vibration exposure.
The daily vibration exposure to be assessed depends on both the average magnitude of vibration at the surface in contact with the hand and the total daily duration for which an employee is in contact with that vibration.
As there is a big difference between a rough estimation of the daily vibration exposure to identify workers at risk and the definition of the state of the art regarding machine vibration emission, vibration total values calculated by applying correction factors are not suitable to determine the state of the art for machine categories. To define the state of the art a high level of accuracy is needed, meaning that this can only be obtained by measurements in all three axes.
Mechanische Schwingungen - Anleitung zur Beurteilung der Belastung durch Hand-Arm-Schwingungen aus Angaben zu den benutzten Maschinen einschließlich Angaben von den Maschinenherstellern
Dieser Fachbericht enthält eine Anleitung zur Abschätzung, Beurteilung und Dokumentation der durch den Einsatz von handgehaltenen und handgeführten Maschinen verursachten Tages-Schwingungsbelastung entsprechend den Anforderungen der europäischen Richtlinie über physikalische Einwirkungen (Vibrationen) 2002/44/EG. Dieser Fachbericht richtet sich an diejenigen fachlichen Stellen, die die Schwingungsbelastung am Arbeitsplatz beurteilen, sowie an Behörden und Organisationen der Arbeitswelt. Er stellt eine Hilfe bei der Erstellung einer Dokumentation über bestimmte Maschinen oder Arbeitssituationen dar und kann auch für Arbeitgeber von Nutzen sein.
Die Vorgehensweise entspricht EN ISO 5349-1 und EN ISO 5349-2, doch anstelle die Schwingungen an den jeweiligen Arbeitsplätzen zu messen, verwenden die Verfahren in diesem Fachbericht Schwingungswerte aus anderen Informationsquellen, zu denen auch die Angaben des Maschinenherstellers entsprechend der Maschinenrichtlinie 98/37/EG zählen. Dabei ist es wesentlich, dass die bei der Beurteilung der Schwingungsbelastung verwendeten Werte für diejenigen bei dem betrachteten Gebrauch der Maschine repräsentativ sind. Messungen am Arbeitsplatz sind jedoch erforderlich, wenn keine Werte zur Verfügung stehen, die die Schwingungen unter den betrachteten Arbeitsbedingungen geeignet repräsentieren, oder wenn die Ergebnisse der Berechnungen zu keiner Entscheidung führen, ob der Grenzwert oder der Auslösewert möglicherweise überschritten ist.
Dieser Fachbericht enthält eine Anleitung, wie sich die Einwirkungsdauer und die Tages-Schwingungsbelastung A(8), wie in EN ISO 5349-1 definiert, abschätzen lassen. Er enthält darüber hinaus ein vereinfachtes Verfahren zur Abschätzung der Tages-Schwingungsbelastung mit Hilfe einer Tabelle, die die Schwingungsbelastung in Abhängigkeit vom äquivalenten Schwingungsgesamtwert und von der zugehörigen Einwirkungsdauer angibt.
Vibrations mécaniques - Guide pour l'évaluation de l'exposition aux vibrations transmises à la main à partir de l'information disponible, y compris l'information fournie par les fabricants de machines
Le présent Rapport technique fournit des principes directeurs pour déterminer, évaluer et documenter l’exposition quotidienne aux vibrations liée à l’utilisation de machines tenues ou guidées à la main, conformément aux exigences de la directive européenne relative aux agents physiques 2002/44/CE et en particulier aux vibrations. Ce Rapport technique est destiné aux services compétents chargés d’évaluer l’exposition aux vibrations sur le lieu de travail, aux autorités et organisations industrielles nationales. Il permettra d’établir une documentation pour des machines ou situations de travail spécifiques et peut également être utile aux employeurs.
Le présent Rapport technique suit la méthode décrite dans l’EN ISO 5349-1 et l’EN ISO 5349-2 mais, au lieu de mesurer les amplitudes de vibration à des postes de travail spécifiques, les méthodes décrites dans ce Rapport technique utilisent les valeurs de vibration existantes provenant d’autres sources d’information et en particulier celles fournies par les fabricants de machines, conformément aux exigences de la directive 98/37/CE relative aux machines. Il est important que les valeurs de vibration utilisées pour évaluer l’exposition soient représentatives de celles générées lors de l’utilisation spécifique de la machine. Toutefois, les mesures réalisées sur le lieu de travail sont requises dans le cas où aucune donnée valable n’est disponible pour représenter la vibration dans les conditions de travail spécifiques ou lorsque les résultats obtenus par le calcul ne permettent pas de déterminer si la valeur limite d’exposition aux vibrations ou la valeur d'exposition déclenchant l'action sont susceptibles d’être dépassées.
Le présent Rapport technique fournit des recommandations sur la méthode à utiliser pour évaluer la durée d’exposition et l’exposition quotidienne aux vibrations A(8) conformément à l'EN ISO 5349-1.
Mehanske vibracije - Smernice za ocenjevanje izpostavljenosti vibracijam preko rok z uporabo podatkov o stroju, vključno s podatki proizvajalca
Standards Content (Sample)
SIST-TP CEN/TR 15350:2007
Mechanical vibration - Guideline for the assessment of exposure to hand-transmitted
vibration using available information including that provided by manufacturers of
Mechanische Schwingungen - Anleitung zur Beurteilung der Belastung durch Hand-Arm-
Schwingungen aus Angaben zu den benutzten Maschinen einschließlich Angaben von
Vibrations mécaniques - Guide pour l'évaluation de l'exposition aux vibrations transmises
a la main a partir de l'information disponible, y compris l'information fournie par les
fabricants de machines
Ta slovenski standard je istoveten z: CEN/TR 15350:2006
13.160 Vpliv vibracij in udarcev na Vibration and shock with
ljudi respect to human beings
SIST-TP CEN/TR 15350:2007 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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Mechanical vibration - Guideline for the assessment of exposure
to hand-transmitted vibration using available information
including that provided by manufacturers of machinery
Vibrations mécaniques - Guide pour l'évaluation de Mechanische Schwingungen - Anleitung zur Beurteilung der
l'exposition aux vibrations transmises à la main à partir de Belastung durch Hand-Arm-Schwingungen aus Angaben zu
l'information disponible, y compris l'information fournie par den benutzten Maschinen einschließlich Angaben von den
les fabricants de machines Maschinenherstellern
This Technical Report was approved by CEN on 6 January 2006. It has been drawn up by the Technical Committee CEN/TC 231.
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, Romania,
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
© 2006 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TR 15350:2006: E
worldwide for CEN national Members.
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CEN/TR 15350:2006 (E)
1 Scope .5
2 Normative references .5
3 Terms and definitions .5
4 Estimation of the vibration magnitude .7
5 Estimation of the daily exposure duration.12
6 Consideration of uncertainties.12
7 Estimation and assessment of the vibration exposure .12
Annex A (informative) Guidance on the information which users could expect from machinery
manufacturers and suppliers .18
Annex B (informative) Principle of the procedure for the estimation of the daily vibration
exposure using manufacturers' declared emission values .20
Annex C (informative) Use of manufacturer’s declared values or other values measured
according to current vibration test codes.21
Annex D (informative) Estimation of the daily vibration exposure for machines with internal
Annex E (informative) Estimation of the daily vibration exposure for electric machines .28
Annex F (informative) Estimation of the daily vibration exposure for pneumatic machines .34
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CEN/TR 15350:2006 (E)
This Technical Report (CEN/TR 15350:2006) has been prepared by Technical Committee CEN/TC 231
“Mechanical vibration and shock”, the secretariat of which is held by DIN.
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CEN/TR 15350:2006 (E)
This Technical Report provides information on how to assess the vibration exposure from hand-held power
tools and hand-guided machines. The methods described use existing vibration emission values declared for
the machine of interest or information coming from other sources. It should be noted that vibration usually
varies a lot over time, with different workstations and different operators. It is therefore not possible to get
precise exposure figures from limited investigations. But also the declared values need to be used with great
care since they are measured for a limited number of defined work situations. The actual work situation for a
specific operator, however, may be very different thus creating different vibration. On the other hand values
from real work that can be found in literature are only correct for the specific work situation and time when
they were measured. The user of this Technical Report should be aware that the exposure to vibration does
not only depend on the machine used but also to a large extent on things like quality of inserted tools, the
work situation and operator behaviour. These factors need to be taken into account to make an ideal
assessment of vibration exposure.
The daily vibration exposure to be assessed depends on both the average magnitude of vibration at the
surface in contact with the hand and the total daily duration for which an employee is in contact with that
As there is a big difference between a rough estimation of the daily vibration exposure to identify workers at
risk and the definition of the state of the art regarding machine vibration emission, vibration total values
calculated by applying correction factors are not suitable to determine the state of the art for machine
categories. To define the state of the art a high level of accuracy is needed, meaning that this can only be
obtained by measurements in all three axes.
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CEN/TR 15350:2006 (E)
This Technical Report gives guidelines for estimating, assessing and documenting the daily vibration
exposure due to the use of hand-held power tools and hand-guided machines, according to the requirements
of the European Physical Agents Directive (vibration) 2002/44/EC. This Technical Report is addressed to
competent services for the assessment of vibration exposure at the workplace and to national authorities and
industrial organizations. It helps to establish documentation for specific machinery or work situations and can
also be useful for employers.
It follows the method of EN ISO 5349-1 and EN ISO 5349-2 but instead of measuring the vibration magnitudes
at the specific workplaces, the methods in this Technical Report use existing vibration values from other
sources of information including those provided by the manufacturers of the machinery according to the
requirements of the Machinery Directive 98/37/EC. It is important that the vibration values used in the
exposure assessment are representative of those in the specific use of the machinery. Workplace
measurements, however, are required if suitable data are not available to represent the vibration under the
specific working conditions or if the calculation results do not help to decide whether or not the vibration
exposure limit value or exposure action value is likely to be exceeded.
This Technical Report gives guidance on how to estimate the exposure duration and the daily vibration
exposure A(8) as defined in EN ISO 5349-1. It also offers a simple method for estimating the daily vibration
exposure by means of a table which indicates the vibration exposure as a function of the equivalent vibration
total value and the associated exposure duration. Both methods can be used even in cases of multiple
exposures on the same day.
Annex A gives guidance for manufacturers and suppliers of machinery concerning information that warns of
risks from vibration, which should be reported to the customer.
2 Normative references
The following referenced documents are indispensable for the application of this Technical Report. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
EN ISO 5349-1, Mechanical vibration — Measurement and evaluation of human exposure to hand-transmitted
vibration — Part 1: General requirements (ISO 5349-1:2001)
EN ISO 5349-2:2001, Mechanical vibration — Measurement and evaluation of human exposure to hand-
transmitted vibration — Part 2: Practical guidance for measurement at the workplace (ISO 5349-2:2001)
3 Terms and definitions
For the purposes of this Technical Report, the terms and definitions given in EN ISO 5349-2:2001 and the
daily duration of the work involving the use of the machinery, i.e. including the interruptions required by the
work and the break periods directly related to the use
NOTE This is more likely to be reported by the operator than the exposure duration (see 3.2).
total duration the hand is in direct contact with the vibrating surface (handle, work piece, etc.)
NOTE The exposure duration is often confused with the user time when estimating the daily exposure duration T
(see Example in 7.2.2).
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CEN/TR 15350:2006 (E)
EXAMPLE The user time for mounting wheels on five automobiles is estimated by the operator at 1 h per day; but
the exposure duration is just 5 cars x 4 lug nuts x 4 wheels x 2 loosening/tightening actions x 4 s which yields T = 0,18 h.
The exposure proportion (see 3.3) is only 18 %.
exposure duration expressed as percentage of the user time
NOTE The exposure proportion varies depending on the machinery and its use. It can be determined in time studies.
Some indication is given in D.2.
equivalent vibration total value
time-averaged sum of the vibration total values of the various machinery operating modes, a , during their
associated exposure durations T :
a = a T (1)
hv,eq ∑ hvi i
NOTE For the vibration total value a , see EN ISO 5349-1. The total exposure duration T for a machine is the sum of
all m individual exposure durations T within the entire work cycle considered (see Table D.1 and Example in 7.2.2). If
there is one operating mode only, then a = a .
partial vibration exposure points
index describing the vibration exposure from a single machine or work task during the associated exposure
P = ×100 (2)
with the equivalent vibration total value a and the associated exposure duration T
NOTE Vibration exposure points are a simple alternative to the A(8) value for describing a person's partial or total
daily vibration exposure. The relationship is:
A(8)= P (3)
This relationship is plotted in Figure 1.
total vibration exposure points
sum of the partial vibration exposure points P within one day:
P = P (4)
Etot ∑ Ei
with n being the number of partial vibration exposures considered
NOTE A score of 100 points for the total vibration exposure in a day is equal to the exposure action value of A(8) =
2,5 m/s and a score of 400 points is equal to the exposure limit value of A(8) = 5 m/s (see Note in 3.5 and Figure 1).
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CEN/TR 15350:2006 (E)
P vibration exposure points
A(8) daily vibration exposure in m/s
Figure 1 — Relationship between the vibration exposure points P and
the daily vibration exposure A(8)
4 Estimation of the vibration magnitude
The vibration magnitude is expressed as a frequency-weighted root-mean-square acceleration value in metres
per second squared (m/s ) as defined in EN ISO 5349-1.
The vibration magnitude for a particular machine can be highly variable. For example, operators, different
operating conditions and different inserted tools all influence the actual magnitude. The magnitude also often
varies over time. It is usually difficult or impossible to obtain a precise value or narrow value range, so an
indication of the average value is all that can be expected. For exposure estimation, it is usually necessary to
take into account the fact that values are obtained within a range of uncertainty (see Clause 6).
4.2 Sources of information
Vibration magnitudes may be measured at the workplace by the employer, or on his behalf. However, this can
be expensive and difficult and it is not always necessary. An important source of information is the
manufacturer or supplier of the machinery. Annex A lists the information employers can expect from
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CEN/TR 15350:2006 (E)
manufacturers and suppliers to help them identify and manage vibration risks. In most cases at present,
especially for older machines, only the declared value in accordance with essential requirement 2.2 of the
Machinery Directive 98/37/EC is available. However, only in the case the vibration test code used for the
determination of the declared vibration emission value is named, a rough estimation of the equivalent vibration
total value can be possible (see Annex C).
There are other sources of information on vibration magnitudes, which are often sufficient to roughly estimate
the daily vibration exposure of workers and help to decide whether the exposure action value or the exposure
limit value is likely to be exceeded.
Some employers are making vibration measurement data available to others in the same industry (often
through trade associations); sharing information in this way can be cost effective for companies using similar
machinery for similar work. Other sources of vibration data include specialist vibration consultants, employers'
organizations (trade associations) and government bodies. Data can also be found in various technical or
scientific publications and on the internet. If data from one of these sources are used, the quality and accuracy
of the data should be checked, e.g. by comparing data from two or more sources; comparing data from
several sources is generally recommended. It should be tried to find a value (or range of values) which
represents the likely vibration magnitude for the particular machine and operating conditions.
4.3 Manufacturers' declared vibration emission values
In the absence of information on vibration in practical use of the machinery, a rough estimation of the vibration
total value can be obtained, in a limited number of cases, from the declared vibration emission value, using
Table D.3, E.1 or F.1. This estimated value should be used only where the information in Annex D, E or F
shows it is likely to be representative of the specific use of the machinery. Where this is not possible,
measurement of the vibration, in accordance with EN ISO 5349-1, will be required for the specific use of the
The principle of the procedure for the estimation of the daily vibration exposure based on existing vibration
values is outlined in Annex B. This method can be used only if all of the following conditions are met:
declared vibration emission values(s) for the machine, and the test code used, are given, e.g. by the
actual operating conditions of the machine are similar to those for which declared values are provided
(detailed information is given in Tables D.3, E.1 and F.1);
machine is in good condition and is maintained in accordance with the manufacturer's recommendations;
inserted tools or attachments are similar to those used for the determination of the vibration emission
4.3.2 Vibration test codes
The vibration values given by manufacturers in their instruction handbooks or other publications (declared
vibration emission values) are determined under standardized measuring and operating conditions which are
defined in the appropriate vibration test code for the family of machines. Following the publication, in 2005, of
EN ISO 20643, the vibration test codes developed should use three axes and give values representative of
the upper quartile of vibration total values produced by the machines in their intended use. However, most
vibration test codes pre-date EN ISO 20643 and do not meet these new requirements.
At present, most vibration test codes pre-date EN ISO 20643 and do not represent the way machines perform
in practical use, and vibration magnitudes at the workplace can be higher or lower than those obtained in this
type of laboratory test. This means that the manufacturer's declared vibration emission value may not be
representative of the real use of the machine.
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CEN/TR 15350:2006 (E)
1) Vibration is not measured at the handle/grip position producing the greatest vibration emission (e.g. current needle
scaler and chipping hammer test codes where vibration is measured at the rear handle but vibration is often greater at
the front hand position);
2) vibration is measured only in one direction, whereas three-axes values should be used for the evaluation of exposure
(most current test codes);
3) specified direction of measurement is not always the axis of highest magnitude (e.g. current needle scaler, chipping
hammer and grinder test codes);
4) specified real or simulated machinery operating mode generates magnitudes below those likely to be found in normal
use (e.g. current grinder test code).
NOTE Many European vibration test codes are currently under review and the revised standards should, in future,
yield vibration emission values which provide a more accurate and realistic guide to likely vibration emissions during the
intended use of the machine (see, e.g., EN ISO 20643).
If the declared vibration emission value is not representative of the vibration likely in the intended use of the
machine, machine manufacturers and suppliers should provide additional information which may include more
appropriate information on likely vibration magnitudes in practical use (see Annex A).
However, only if the vibration test code used for the determination of the declared vibration emission value is
named, a rough estimation of the vibration total value can be performed using Table D.3, E.1 or F.1.
4.3.3 Interpreting manufacturers' declared vibration emission values
If the machine manufacturer or supplier is unable to confirm that the declared vibration emission value (and
uncertainty K) represent the vibration in the intended use, and does not provide additional information, then
the employer may need to seek information from other sources or make measurements at the workplace in
order to assess the exposure of his employees (see 4.2 and 4.4).
Manufacturers will usually not publish vibration emission values if they are below 2,5 m/s but in this case they
must state that it is less than 2,5 m/s . In this case the value of 2,5 m/s shall be used and the correction
factors given in the annexes should be used.
NOTE Also when vibration emission values below 2,5 m/s are given and reference is made to emission standards
that pre-dated EN ISO 20643 it is recommended to use 2,5 m/s for exposure assessment instead of the declared value
In the following, influences of various parameters and conditions are discussed. The consequences
emanating from some of these influences are described in Annexes D, E and F.
220.127.116.11 Influence of machine operating conditions
Vibration test codes should specify operating conditions for the machine while the vibration emission is
measured. The operating conditions given in most test codes were developed to be reproducible, and in some
cases this has resulted in artificial operating conditions. For example, grinders are tested while free-running
(not grinding) and fitted with an aluminium test wheel of known unbalance; chipping hammers and breakers
are operated against an artificial loading device. EN ISO 20643 states that operating conditions based on a
typical real working situation are preferred to artificial conditions, and that the operating conditions should be
selected to represent the highest vibration likely to occur in typical and normal use of the machine. However,
in some vibration test codes that pre-dated EN ISO 20643 the operating conditions can produce vibration
emission values which do not give a good representation of typical use of the machine.
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CEN/TR 15350:2006 (E)
In some cases, such as machines powered by internal combustion engines, vibration emission measurements
according to (mostly newer) vibration test codes are made separately for different modes of operation (e.g.
idling, racing and cutting for a chain saw) and the equivalent vibration total value a (see 3.4) is calculated
from several a values using standardized assumptions regarding the proportions of the exposure duration for
each operating mode (see Table D.2). If necessary, a can be recalculated using proportions more
representative of the work being assessed.
Tables D.3, E.1 and F.1 contain current vibration test codes and list categories for the operating modes as
specified in these standards. The tables give some indications of how the operating mode of the vibration test
code influences the declared vibration emission value and how this compares with likely vibration magnitudes
in real use.
Table D.2 shows how, for some types of machines, a typical work cycle is composed of several operating
In some cases it may be possible to obtain a more realistic vibration emission value than that measured using
the vibration test code by applying a correction. It is not always important (or possible) to be accurate or
precise when doing this. For example, if the daily exposure, calculated using manufacturer's emission value,
is just below the exposure limit value, and the test code is thought likely to produce low values, it is
reasonable to conclude that the limit value is likely to be exceeded and that preventive action is required.
18.104.22.168 Influence of vibration measurement direction and location
Vibration of most surfaces in contact with the hand (such as machine handles) is rarely in one direction only.
Therefore, according to the Directive 2002/44/EC and EN ISO 5349-1, vibration is measured in three separate
directions (x-, y- and z-axes) at right angles to one another. The three measured values are combined to give
a single magnitude, the vibration total value a (see EN ISO 5349-1).
However, if according to a (mostly older) vibration test code only the vibration magnitude measured in one
direction is available the vibration total value a can be estimated by applying a correction factor. For many
typical hand-held electric or pneumatic machines, the a value is suitable (with an appropriate value for
exposure duration, see Clause 5) for estimating the daily vibration exposure if the conditions in 4.3.1 are met.
The vibration emission values obtained using several – particularly older – test codes are based on
measurements made in a single specified direction, at a single specified measurement location. In some
cases, it is also difficult to conduct vibration measurements along all three axes. In cases where a value has
been measured in the dominant vibration axis, a , the vibration total value a can be estimated with the aid
of a correction factor:
a = c a (5)
The correction factor c falls within the range 1,0 to 1,7 and for an individual machine can fall anywhere in this
range. For percussive machines, a correction factor of 1,2 is typical if the machine is not equipped with an
anti-vibration system, and for pure rotary and reciprocating machines a correction factor of about 1,4 is typical.
The correction factors given in Tables D.3, E.1 and F.1 for individual families of machinery include appropriate
values for this correction factor.
Some current test codes require vibration to be measured at a location which is not the hand position of
greatest vibration exposure (e.g., the rear handle of a chipping hammer or needle scaler is not usually the
hand position of greatest vibration). In these cases it is difficult to estimate the magnitude of vibration to which
the operator is exposed to both hands by using the declared emission value. However, the knowledge that the
true magnitude in real use is greater than the declared value can be sufficient to assess the risk in some
cases, such as when demonstrating that the exposure limit value is exceeded.
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CEN/TR 15350:2006 (E)
22.214.171.124 Influence of age and condition of the machine
The manufacturer's declared vibration emission values are determined using new or almost new machines.
Irregular or poor maintenance of machines can lead to substantial changes in the vibration emissions,
depending on the type of machine in question. Current knowledge of the influence of the aging process is
quite poor, particularly for some machines with anti-vibration systems.
Employers should ensure that machines are maintained in accordance with the manufacturer's
recommendations. The vibration emission (according to the vibration test code) is then likely to be in the range
indicated by the manufacturer.
126.96.36.199 Influence of anti-vibration systems and resilient grips
Some test codes specify a steady-state operating condition and have been developed before modern designs
of machinery with vibration reduction features (e.g. breakers with isolating handles or grinders with anti-
vibration systems). The emission values obtained with the vibration test code can deviate greatly from the
vibration magnitudes measured under real operating conditions.
Constantly changing conditions in practical use, such as frequent shut-off and power-on processes, can limit
the effectiveness of the vibration reducing features like resiliently mounted handles on rotary machines.
Changing the feed force in real conditions can limit the effectiveness of suspended handles of breakers,
particularly if the operator has not been trained to use the machine as the manufacturer intended. Thus, test
code operating conditions can produce vibration values which are lower than those found in real use.
188.8.131.52 Influence of inserted tools
In most work situations the properties of the inserted tools have great influence on the vibration emission.
Most vibration test codes therefore precisely define the properties of the inserted tools used for the test. In
some cases artificial inserted tools (e.g. an unbalanced disc on a grinder) are used. When the inserted tools
used in the real work situation are different from those defined in the vibration test code the vibration values
may be considerably higher or lower. The machine manufacturer or supplier may have additional information
on the vibration emission with different inserted tools. To control the vibration in a real work situation it can be
important to choose good quality inserted tools that are suitable for the machine.
4.4 Making vibration measurements
There may be situations in which the vibration exposures cannot adequately be estimated. It may then be
necessary to make measurements at the workplace.
1) A vibrating machine is used for an unusual purpose, of which the manufacturer has limited previous experience and
so cannot provide vibration information;
2) it may not be clear, from the limited information available, whether the exposure action value or the exposure limit
value is likely to be exceeded;
3) employer may wish to check the effectiveness of actions taken to control vibration exposure.
Further information and practical guidance on exposure evalu