IEC 60068-2-86:2024

IEC 60068-2-86 ®
Edition 1.0 2024-02
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Environmental testing –
Part 2-86: Tests –Test Fx: Vibration – Multi-exciter and multi-axis method

Essais d'environnement –
Partie 2-86: Essais – Essai Fx: Vibrations – Méthode par excitateurs multiples et
axes multiples
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IEC 60068-2-86 ®
Edition 1.0 2024-02
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Environmental testing –
Part 2-86: Tests –Test Fx: Vibration – Multi-exciter and multi-axis method

Essais d'environnement –
Partie 2-86: Essais – Essai Fx: Vibrations – Méthode par excitateurs multiples et

axes multiples
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 19.040  ISBN 978-2-8322-8242-7

– 2 – IEC 60068-2-86:2024 © IEC 2024
CONTENTS
FOREWORD . 4
1 Scope . 6
2 Normative references . 7
3 Terms and definitions . 8
4 Background . 9
4.1 General . 9
4.2 Multi-axis and/or multi-exciter testing to achieve an improved distribution of
dynamic responses . 9
4.3 Multi-exciter testing for large equipment. 10
4.4 Multi-axis testing for reliability growth . 10
4.5 Multi-axis testing to reduce test durations . 10
5 Test apparatus and control strategy . 11
6 Test severities and tolerances . 11
6.1 Test severities . 11
6.2 Tolerances . 11
6.3 Excitations outside the specified test frequency range . 11
6.4 Cross-axis motions . 12
7 Mounting of specimen and installation of measurement systems. 12
8 Precursor testing . 13
9 Vibration response investigation . 13
10 Pre-conditioning . 13
11 Initial measurement and functional performance test . 14
12 Low level excitation for equalisation prior to testing . 14
13 Testing . 14
14 Intermediate measurement and functional performance . 14
15 Recovery . 14
16 Final measurement and functional performance and vibration response
investigation . 15
17 Test verification . 15
18 Information to be specified in the relevant specification . 15
19 Information to be given in the test report. 16
Annex A (informative) Guidance on multi-axis and multi-exciter test control systems . 18
A.1 General . 18
A.2 Multi-exciter control strategies . 18
A.3 Determined and over determined control strategies . 19
A.4 Quantifying the inter-relationship between exciters for vibration testing . 20
A.5 Quantifying the inter-relationship between exciters for time history
replication testing. 21
Annex B (informative) Additional testing guidance . 23
B.1 Fixing, monitor, control and reference points . 23
B.2 Control equalisation . 23
B.3 Cross-axis motion, signal distortion and out of test frequency range
responses . 24
B.4 Precursor testing . 25
B.5 Vibration response investigation . 25

B.6 Temperature conditioning and stabilization . 25
B.7 Performance evaluation . 26
B.8 Verification of test procedure . 26
Annex C (informative) Guidance on the application of multi-axis / multi-vibrator tests . 28
C.1 General . 28
C.2 Advice on using multi-exciter systems for the testing of large specimens . 28
C.2.1 General . 28
C.2.2 Data measurements . 28
C.2.3 Multi-exciter test fixture . 28
C.2.4 Test control . 29
C.2.5 Testing . 29
C.3 Advice on using multi-axis systems for multi-degree of freedom testing . 29
C.3.1 General . 29
C.3.2 Data measurements . 30
C.3.3 Multi-exciter test fixture . 30
C.3.4 Test control . 30
C.3.5 Testing . 30
C.4 Advice on using multiple shakers attached directly to the specimen via
flexible couplings . 31
C.4.1 General . 31
C.4.2 Data measurements . 31
C.4.3 Multi-exciter test fixture . 32
C.4.4 Test control . 33
C.4.5 Interrelationship in testing. 34
Annex D (informative) Guidance on the use of measured data for multi-axis/multi-
vibrator tests . 35
D.1 General . 35
D.2 Use of measured data to derive test severities . 35
Annex E (informative) Guidance on the selection of test tolerances . 37
E.1 General . 37
E.2 Test tolerances associated with measured data . 37
E.3 Test tolerances applicable to different parameters . 37
Bibliography . 39

Figure A.1 – Power Spectral Density (PSD) and Cross-Spectral Density (CSD) for a
two exciter system . 20
Figure A.2 – Power Spectral Density (PSD) and Cross-Spectral Density (CSD) for a six
exciter system . 20
Figure C.1 – Examples of spherical bearings . 33

Table E.1 – Test tolerances applicable to different parameters . 38

– 4 – IEC 60068-2-86:2024 © IEC 2024
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ENVIRONMENTAL TESTING –
Part 2-86: Tests – Test Fx: Vibration –
Multi-exciter and multi-axis method

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and
in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports,
Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their
preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with
may participate in this preparatory work. International, governmental and non-governmental organizations liaising
with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for
Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
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4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
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any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
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6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
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expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) IEC draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). IEC takes no position concerning the evidence, validity or applicability of any claimed patent rights in
respect thereof. As of the date of publication of this document, IEC had not received notice of (a) patent(s), which
may be required to implement this document. However, implementers are cautioned that this may not represent
the latest information, which may be obtained from the patent database available at https://patents.iec.ch. IEC
shall not be held responsible for identifying any or all such patent rights.
IEC 60068-2-86 has been prepared by IEC technical committee 104: Environmental conditions,
classification and methods of test. It is an International Standard.
The text of this International Standard is based on the following documents:
Draft Report on voting
104/1035/FDIS 104/1043/RVD
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.

This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/publications.
A list of all parts in the IEC 60068 series, published under the general title Environmental
testing, can be found on the IEC website.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the
specific document. At this date, the document will be
• reconfirmed,
• withdrawn, or
• revised.
– 6 – IEC 60068-2-86:2024 © IEC 2024
ENVIRONMENTAL TESTING –
Part 2-86: Tests – Test Fx: Vibration –
Multi-exciter and multi-axis method

1 Scope
This document provides a test procedure for use with multi-exciter and multi-axis vibration test
systems. The vibration test is intended for general application to components, equipment, and
other products, hereinafter referred to as "specimens", subjected to dynamic environments that
could arise during an equipment life cycle. Although this document is mainly intended for
vibration testing, the procedure is also applied to certain types of shock and transient tests.
The test procedure set out in this document is applicable where a specimen is required to
demonstrate its adequacy to resist specified vibration, shock and transient conditions, without
unacceptable degradation of functional or structural performance. The test procedure has
significant similarity to test procedures of other IEC 60068-2 documents and encompasses the
same range of vibration and shock excitation types.
This document is applicable to specimens subjected to vibration, shock and transient conditions
resulting from transportation and/or operational environments, for example in aircraft, space
vehicles and land vehicles. It is primarily intended for unpackaged specimens. It is applicable
to specimens in their transportation container when the latter are considered as part of the
specimen itself.
The test method and associated techniques addressed within this document are primarily
intended for use with multiple electrodynamic or servo-hydraulic vibration generators along with
an associated computer-based digital control system to control of the specimen excitations.
This document encompasses two testing approaches, commonly referred to as multi-exciter
single-axis (MESA), and multi-exciter multi-axis (MEMA). These are:
a) Utilising fixed base shakers either in a single axis or a selected combination of fixed X, Y,
Z configurations, also allowing for rotations dependent upon fixture coupling design.
b) Utilising multiple shakers attached directly to the specimen via flexible couplings or similar
methods. Here the shakers are attached at any point and in any direction on the specimen.
This approach is quite similar to that used for modal testing, but using environmental test
severities.
It is emphasised that MESA and MEMA testing currently requires a high degree of engineering
judgement and relevant experience, and both test specifier and tester are fully aware of this
fact. Generally, MESA and MEMA testing requires greater resources to set up an appropriate
test, but potentially provides a more accurate outcome.
For the purpose of this document, the creator of the relevant testing specification, the test
specifier, is expected to select the procedure and the values of severity appropriate to the
specimen and its use. Precursor testing is included within the procedure of this document, as
an option, to permit the test specifier to establish the practicality of the test specification and
severities with the specimen. A separate specimen is usually provisioned for such precursor
testing.
The existing single axis, single vibrator test procedures within the IEC 60068-2 series can be
used with a wide range of different excitations, such as broad band random, random on random,
sine on random, swept sine, shock, and long-time history replication. Theoretically these
different forms of excitations, can also be applied using multi-axis and multi-exciter methods.
However, suitable techniques and commercially available test control software, for some of
these types of testing, are not necessarily currently commonly available. For this reason, the
procedure of this document is currently primarily intended for broad band random and time
history replication as facilities to undertake these types of tests are commonly available. With
that said, the procedure of this document may be adapted, by the user, for other forms of
excitation and advice is provided.
Traditionally, vibration, shock and transient test severities are specified using acceleration as
the control parameter. However, this is not an essential pre-requisite of the procedure within
this document. For the purpose of this document, vibration, shock and transient test severities
are specified by the user and may be in the form of acceleration, velocity, displacement, or
force. The need to include different control parameters within this document arises because
there is a greater likelihood when using multi-exciter testing to specify mixed parameters for
control purposes. In which case the vibration, shock and transient waveforms applied to the
specimen will be controlled based upon the feedback from transducers measuring the
appropriate parameter.
Although primarily intended for electrotechnical specimens, this document is not restricted to
them and may be used in other fields where desired.
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.
IEC 60068-1, Environmental testing – Part 1: General and guidance
IEC 60068-2-6, Environmental testing – Part 2-6: Tests –Test Fc: Vibration, (Sinusoidal)
IEC 60068-2-27, Environmental testing – Part 2-27: Tests – Test Ea and guidance: Shock
IEC 60068-2-57, Environmental testing - Part 2-57: Tests – Test Ff: Vibration – Time-history
and sine-beat method
IEC 60068-2-64, Environmental testing – Part 2-64: Tests –Test Fh: Vibration, broadband
random and guidance
IEC 60068-2-80, Environmental testing – Part 2-80: Tests –Test Fi: Vibration – Mixed mode
IEC 60068-2-85, Environmental testing – Part 2-85: Tests –Test Fj: Vibration – Long time
history replication
ISO 2041, Mechanical vibration, shock and condition monitoring – Vocabulary

– 8 – IEC 60068-2-86:2024 © IEC 2024
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 2041, IEC 60068-1,
IEC 60068-2-6, IEC 60068-2-27, IEC 60068-2-57, IEC 60068-2-64, IEC 60068-2-80 and
IEC 60068-2-85 and the following apply.
ISO and IEC maintain terminology databases for use in standardization at the following
addresses:
• IEC Electropedia: available at https://www.electropedia.org/
• ISO Online browsing platform: available at https://www.iso.org/obp
3.1
multi-exciter single-axis
MESA
method of applying vibration test waveforms using multiple vibration exciters, but all applying
the vibrations in a single specimen axis
3.2
multi-exciter multi-axis
MEMA
method of applying vibration test waveforms using multiple vibration exciters in two or more
specimen axis
Note 1 to entry: The applied excitations may be in the translation axes, rotational axes or both translation and
rotational axes.
3.3
single-input single-output
SISO
method of applying vibration test waveforms using input of a single drive signal to an exciter
system in a single-degree of freedom configuration and a single measured output from the test
specimen or its fixing points in a single-degree of freedom configuration
Note 1 to entry: This is essentially a conventional single axis/exciter test arrangement using a single measured
response for control purposes.
3.4
single-input multiple-output
SIMO
method of applying vibration test waveforms using input of a single drive signal to an exciter
system in a single degree of freedom configuration, and multiple measured outputs from the
test specimen or its fixing points in a multi-degree of freedom configuration
Note 1 to entry: This is essentially an extension of a conventional single axis/exciter test arrangement, but
manipulating multiple measured responses for control purposes.
3.5
multiple-input single-output
MISO
method of applying vibration test waveforms using input of multiple drive signals that are applied
to the multiple exciters, to produce a single measured output from the test specimen or its fixing
points
Note 1 to entry: Unless the multiple inputs are applying the identical waveform, this arrangement is often not
possible as multi-exciter test control systems often require the number of outputs to match the number of inputs.

3.6
multiple-input multiple-output
MIMO
method of applying vibration test waveforms using input of multiple drive signals that are applied
to the exciters, to produce multiple measured outputs from the test specimen or its fixing points
Note 1 to entry: Commonly, as a minimum, the number of inputs and outputs should be the same, but many systems
used for multi-exciter control, allow the number of outputs to exceed the number of inputs. Commonly, multi-exciter
and multi-axis test control systems operate as multiple-input multiple-output systems.
4 Background
4.1 General
The capability to undertake multi-exciter testing has been available for some time for seismic
as well as durability / fatigue testing. Generally, such tests utilise excitations which occur at
relatively low frequencies. It is only comparatively recently that capabilities have become
commonly available to undertake multi-axis and/or multi-exciter tests, at frequencies necessary
for general purpose vibration, shock and transient testing.
The use of multi-axis and/or multi-exciter testing equipment [1] for certain types of vibration,
shock and transient testing is currently perceived as having advantage in a number of
applications, some of which are set out below. This list should not be considered as exhaustive
as applications for multi-axis and/or multi-exciter testing are still being identified. Broadly the
advantages of multi-axis and/or multi-exciter testing include better loading distribution, more
realistic excitations, and the potential for test time reduction.
4.2 Multi-axis and/or multi-exciter testing to achieve an improved distribution of
dynamic responses
Multi-axis and/or multi-exciter testing is in regular use for large and/or dynamically complex
specimens, where there is a need to ensure that the dynamic response motions of the specimen
are correctly achieved. In such cases multi-exciter testing can achieve a far more accurate
distribution of dynamic responses than the traditional vibration, shock and transient testing
methods. This is particularly the case when the specimen would experience, in-service, dynamic
excitations from multiple excitation sources. An example of this would be a road vehicle were
somewhat different dynamic excitations arise from each wheel.
Using multi-axis and/or multi-exciter testing to achieve an improved distribution of dynamic
responses within a specimen, usually requires test severities which are derived from vibration,
shock or transient data, measured during actual life cycle conditions. The applied dynamic
excitations are commonly controlled from measurements at multiple response locations. This is
essentially a "controlled response" test control strategy. This is a fundamentally different control
strategy, to that used for the majority of the single axis vibration, shock and transient tests
within IEC 60068-2. Those single axis tests are basically "controlled excitation" tests both
applying and controlling the excitations to the specimen’s fixing points. Such a control strategy
is not profoundly influenced by the dynamic responses of the specimen. Consequently, the test
severities for such "controlled excitation" tests can readily adopt "generic" severities as the
severities are independent of the dynamic responses of the specimen.
For some applications "generic" severities have advantage in that they may represent a wide
range of life cycles conditions. For example, the generic test severities for transportation
encompass a range of usage conditions and a variety of transportation platforms. The use of
simple generic test severities with multi-axis and/or multi-exciter testing may limit the ability to
achieve an accurate distribution of dynamic responses.
___________
Numbers in square brackets refer to the Bibliography.

– 10 – IEC 60068-2-86:2024 © IEC 2024
4.3 Multi-exciter testing for large equipment
Multi-exciter testing is sometimes used as a testing convenience, permitting the use of several
smaller exciters rather than a single much larger (and more expensive) exciter. In this case the
use of multi-exciter testing can permit the testing of equipment which otherwise would not be
practicable. As an example, four vibrators could be (electrically and mechanically) coupled
together to provide a facility to test very large specimens such as entire vehicles. If the
waveforms applied to each exciter are correlated, then such a setup is essentially that of a
conventional single axis test procedure and comparable test severities could be adopted. If the
waveforms are not correlated, then the procedure of this document would be more applicable.
In such cases the test severities may be defined either as applied excitations to the specimen
fixing points or as specimen responses. In either case, the testing arrangement means that the
test will need to be controlled using a "controlled response" strategy.
Although the use of generic test severities is a possibility when using this type of test approach,
the phase and amplitude relationship between the excitations will still need to be derived with
some knowledge of actual relationships. This is necessary as, without such knowledge, the
dynamic conditions experienced by the specimen may well be significantly increased and/or
decreased in an indeterminate way from that of a single axis test.
4.4 Multi-axis testing for reliability growth
Multi-axis testing has been perceived as having advantage for reliability growth testing of
certain types of electro-technical equipment. This is because the multi-axis dynamic responses
produced within the specimen are different, in many ways, to those produced during single axis
testing. The multi-axis dynamic responses produced are considered to exercise a greater
number of potential failure and degradations modes of the specimen than the conventional
single axis testing.
The test severities used for reliability growth testing are generally exaggerated (viz. greater
than those likely to be experienced in-service) and applied at the fixing points of the specimen.
For this specific purpose, the use of generic test severities may be appropriate. Nevertheless,
the dynamic responses within the specimen may not necessarily represent conditions which
actually occur during the specimen life cycle. For this reason, failures identified by such test
are commonly the subject of a reliability failure assessment, to ensure they could realistically
occur during the equipment’s life cycle.
4.5 Multi-axis testing to reduce test durations
Multi-axis testing has sometimes been proposed as a testing convenience for reducing the
duration of applied excitation. Simplistically, by applying excitations in all three-axis
simultaneously, the test duration can be reduced by a third from that of single axis tests
undertaken in three axes separately. It may also achieve savings in that only one test set up is
required. However, these savings may not necessarily be fully achieved as the multi-axis test
set up may be more complicated to achieve. When coupled with the purpose of achieving an
improved distribution of dynamic responses, such a saving may not always possible, as the use
of more realistic severities may also require them to be applied for longer durations.
There can also be a concern when multi-axis testing is used with generic severities to achieve
a test duration reduction. This is because the phase and amplitude relationship utilised between
the different excitation axes, will produce indeterminately increased and/or decreased dynamic
conditions with the specimen from those of three separate single axis tests. Commonly generic
severities are based upon long historic experience with the existing single axis test. As such it
may not be realistic to compare the outcome of multi-axis testing, undertaken with generic
severities, with the outcome of historic single axis tests.

5 Test apparatus and control strategy
The use of any multi-exciter or multi-axis test system, capable of satisfying the test
requirements, is acceptable [1]. The capability of the excitation equipment and control facility
to conduct the test, as specified in the relevant specification, shall be verified prior to
undertaking the test.
Guidance information on multi-exciter / multi-axis test control systems is provided in Annex A.
Guidance on the application of different control strategies is provided in Annex B. Guidance on
the use of different multi-exciter / multi-axis test configuration is provided in Annex C. Further
general guidance on multi-exciter and multi-axis testing can be found in [2], [3], [4] and [5].
6 Test severities and tolerances
6.1 Test severities
The test severities utilised shall be those specified in the relevant specification. Unless
specified otherwise, the severities and other parameters necessary to undertake this test should
be based on the purpose for which it is being conducted and on the conditions the specimen is
likely to experience during its life cycle.
Guidance information on establishing severities for multi-exciter / multi-axis testing is provided
in Annex D.
6.2 Tolerances
The measured control responses shall not deviate from the specified requirements by more
than the test tolerances quoted in the relevant specification.
Unless specified otherwise the tolerance on:
a) Power spectral density values, of a Gaussian random vibration test, shall be within ±3 dB of
the specified values.
b) Time history amplitudes, of a time history replication test, shall be within ±20 % of the
highest amplitude of the specified waveform for at 90 % of the specified waveform duration.
The test tolerances shall not be used to modify the specified requirements.
Any deviation from the specified tolerances shall be agreed with the relevant test specifier and
the actual tolerances achieved, and reason for the deviation, stated in the test report. In order
to achieve such an agreement, it is recommended that the verification measurements set out in
Annex B should be made available to the relevant test specifier.
Guidance information on the selection of suitable tolerances for multi-exciter / multi-axis testing
is provided in Annex E.
6.3 Excitations outside the specified test frequency range
Excitations outside the specified test frequency range shall be minimised and if required
quantified. The approach to be used to quantify excitations outside the specified test frequency
range, if required, shall be specified in the relevant specification. Guidance information on
establishing severities for multi-exciter / multi-axis testing is provided in Annex B.
Unless specified otherwise the out of test frequency range excitations shall be established as
set out below.
a) Random vibration: For random vibration tests, including all the vibration tests, which have
broad band and narrowband random components, the out of test frequency range responses

– 12 – IEC 60068-2-86:2024 © IEC 2024
shall be established up to 5 000 Hz or 5 times the driving frequency, whichever is the lesser.
The out of test frequency range responses shall be established in accordance with the
procedure of IEC 60068-2-64, although it should be noted that the procedure of
IEC 60068-2-64 is specifically related to the use of acceleration as a control parameter.
b) Time history replication: For time signal replication tests the out of test frequency range
responses shall be established up to 10 000 Hz or 10 times the driving frequency, whichever
is the lesser. The out of test frequency range responses shall be established in accordance
with the procedure of IEC 60068-2-85.
c) Sinusoidal tests: For sinusoidal vibration tests (fixed, swept and stepped) the signal
tolerance shall be established up to 5 000 Hz or 5 times the driving frequency, whichever is
the lesser. This parameter applies whether the signal is acceleration, velocity, or
displacement. The signal tolerance shall be established in accordance with the procedure
of IEC 60068-2-6.
6.4 Cross-axis motions
The relevant specification shall specify whether cross-axis motions are to be controlled. If there
is a requirement to control cross-axis motions, then the relevant specification shall also specify
the approach to be used to quantify the cross-axis motions and the appropriate tolerance.
If cross-axis motions are of concern and no requirements are provided in the relevant
specification, then the following are recommended.
a) Random vibration: should not exceed -3 dB of the highest specified spectral acceleration
for each control axis for each frequency up to 500 Hz or 0 dB for higher frequencies in
accordance with IEC 60068-2-64.
b) Sine vibration: should not exceed 50 % of the highest specified acceleration for each control
axis for each frequency up to 500 Hz or 0 dB for higher frequencies in accordance with
IEC 60068-2-6.
c) Time history replication: should not exceed 50 % of the highest specified acceleration for
each control axis at each time step in accordance with IEC 60068-2-85.
Any deviation from the specified cross-axis requirements shall be agreed with the relevant test
specifier and the actual cross axes motions achieved, and reason for the deviation, stated in
the test report. In order to achieve such an agreement, it is recommended that the verification
measurements set out in Annex B should be made available to the relevant test specifier.
Further guidance information on cross-axis motions for multi-exciter/multi-axis testing is
provided in Clause B.3.
7 Mounting of specimen and installation of measurement systems
The specimen shall be mechanically connected to the multi-exciters and fixtures, in the required
orientation and state, as specified in the relevant specification. Unless specified otherwise, the
specimen shall be held by its normal means of attachment. The specimen installation shall
include, as required, any connections necessary for power supplies, test signals, performance
monitoring and any monitoring instrumentation, to establish the responses from the test
specimen.
General guidance on the mounting of specimens for vibration testing is provided in
IEC 60068-2-47 [6]. However, the guidance and normative requirements of IEC 60068-2-47 are
intended for single axis testing, they are not necessarily fully applicable to multi-exciter testing.
Additional guidance on test fixtures and the mounting of specimens, applicab
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