IEC 60068-2-55:2013

IEC 60068-2-55 ®
Edition 2.0 2013-02
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
BASIC SAFETY PUBLICATION
PUBLICATION FONDAMENTALE DE SÉCURITÉ
Environmental testing –
Part 2-55: Tests – Test Ee and guidance – Loose cargo testing including bounce

Essais d’environnement –
Partie 2-55: Essais – Essai Ee et guide – Essais de chargement sans arrimage y
compris l’essai de rebondissement

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IEC 60068-2-55 ®
Edition 2.0 2013-02
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
BASIC SAFETY PUBLICATION
PUBLICATION FONDAMENTALE DE SÉCURITÉ

Environmental testing –
Part 2-55: Tests – Test Ee and guidance – Loose cargo testing including bounce

Essais d’environnement –
Partie 2-55: Essais – Essai Ee et guide – Essais de chargement sans arrimage y

compris l’essai de rebondissement

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX R
ICS 19.040; 29.020 ISBN 978-2-83220-644-7

– 2 – 60068-2-55 © IEC:2013
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Requirements for the test apparatus . 7
4.1 General test description . 7
4.2 Characteristics of the testing machine . 7
4.3 Motion of the platform . 7
4.4 Tolerances on the horizontal accuracy of platform . 8
4.5 Control . 8
4.6 Mounting . 8
4.7 Horizontal motion of specimen. 8
5 Severities . 8
5.1 Severity for sinusoidal motion of the platform . 8
5.2 Severity for random motion of the platform . 9
5.3 Severity for mixed mode motion of the platform . 9
5.4 Severity for use of special bounce testing machines . 9
6 Preconditioning . 9
7 Initial measurements and functional performance test . 9
8 Testing . 9
9 Recovery . 10
10 Final measurements . 10
11 Information to be given in the relevant specification. 11
12 Information to be given in the test report . 11
Annex A (normative) Guidance . 12
Annex B (informative) Comparison amongst impact tests . 17
Bibliography . 18

Figure A.1 – Typical arrangement of barriers and typical reference point positions . 13
Figure A.2 – Basic drive motion of a mechanical bounce tester . 14

Table B.1 – Comparison of different impact tests . 17

60068-2-55 © IEC:2013 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ENVIRONMENTAL TESTING –
Part 2-55: Tests – Test Ee and guidance –
Loose cargo testing including bounce

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
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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) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 60068-2-55 has been prepared by IEC technical committee 104:
Environmental conditions, classification and methods of test.
This second edition cancels and replaces the first edition, published in 1987, and constitutes
a technical revision.
The main changes with respect to the previous edition are listed below:
This new edition allows for loose cargo testing in a more general sense. The test is no longer
aligned with a special testing machine but allows for use of any suitable equipment such as
electrodynamic or servo-hydraulic shaker tables. Moreover, sinusoidal and random vibration
can be used. The previous rotation table motions are included in Annex A as historical
methods.
– 4 – 60068-2-55 © IEC:2013
The text of this standard is based on the following documents:
FDIS Report on voting
104/592/FDIS 104/598/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
It has the status of a basic safety publication in accordance with IEC Guide 104.
This standard should be used in conjunction with IEC 60068-1.
A list of all the parts in the IEC 60068 series, under the general title Environmental testing,
can be found on the IEC website.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
60068-2-55 © IEC:2013 – 5 –
INTRODUCTION
This test is applicable to specimens which, during transportation on the load-carrying platform
of wheeled vehicles either not fastened down or with some degree of freedom, may be
subjected to dynamic stresses resulting from random shock conditions (bounce). The test may
also be used as a simple means of assessing the satisfactory design of a specimen so far as
its structural integrity is concerned.
NOTE In practice, this test is primarily applicable to equipment-type specimens and packages.
Although the test is performed using a vibrating platform, it is not considered as a vibration
test, but as an impact test. Vibration tests should be conducted according to the appropriate
standards from IEC 60068-2.
In Clause 11, specification writers will find a list of details to be considered for inclusion in
specifications and, in Annex A, the necessary accompanying guidance.

– 6 – 60068-2-55 © IEC:2013
ENVIRONMENTAL TESTING –
Part 2-55: Tests – Test Ee and guidance –
Loose cargo testing including bounce

1 Scope
This part of IEC 60068 provides a standard procedure for determining the ability of a
specimen to withstand specified severities of bounce, e. g. when transported as loose cargo
on wheeled vehicles.
This test is primarily intended for specimens prepared for transportation, including specimens
in their transport case when the latter may be considered as part of the specimen itself or
packages. This test should not be used as a low-frequency vibration test.
Although primarily intended for electrotechnical products, this standard is not restricted to
them and may be used in other fields where desired.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and
are indispensable for its application. 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 60068-2-64, 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
ISO 13355, Packaging – Complete, filled transport packages and unit loads – Vertical random
vibration test
ASTM D4169-09, Standard Practice for Performance Testing of Shipping Containers and
Systems
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
bounce testing machine
testing machine with a vibrating platform driven by rotating shafts and eccentrics
Note 1 to entry: Bounce testing machines typically have a fixed displacement amplitude and a variable frequency.
___________
A new edition of IEC 60068-1 is currently under consideration.

60068-2-55 © IEC:2013 – 7 –
3.2
checkpoint
point located on the vibration table
Note 1 to entry: For the purpose of this standard, the checkpoints have to be located on the vibration table,
regardless of the position of the specimen.
3.3
reference point
point, chosen from amongst the checkpoints, whose signal is used to control the test, such
that the requirements of this standard are satisfied
3.4
g
n
standard acceleration due to the earth's gravity, which itself varies with altitude and
geographical latitude
Note 1 to entry: For the purposes of this standard, the value of g is rounded up to the nearest whole number,
n
that is 10 m/s .
4 Requirements for the test apparatus
4.1 General test description
The specimen is installed on a vibrating platform without a fixture and occasionally bounces,
according to the mass and stiffness of the platform and the specimen, and the prescribed
motion. No direct control is imposed on the specimen motion. Wherever possible, the test
severity applied to the specimen shall be related to the operational environment to which the
specimen will be subjected during transportation.
The relevant specification shall state the criteria upon which the acceptance or rejection of the
specimen is to be based. Normally, for this test the specimen is not functioning and it is
sufficient that it should survive the testing.
4.2 Characteristics of the testing machine
The testing machine shall consist of a horizontal platform coupled to a shaker or a similar
drive mechanism. If prescribed by the relevant specification, special bounce testing machines
may be used (see Clause A.3).
The platform shall be of at least 24 mm and not to exceed 32 mm plywood firmly attached to a
suitable stiff frame, if required, with appropriate barriers (see 4.7). It shall be of sufficient size
to support the specimen. Furthermore, the characteristics of the testing machine shall allow
for the prescribed motion of the platform, see 4.3.
4.3 Motion of the platform
The motion of the platform shall be vertical linear, also when loaded by the specimen and any
other devices necessary for conducting the test. A rotary motion of the platform is not possible
when connected to a shaker table. The relevant specification can prescribe sinusoidal or
random vibration of the platform.
The deflections of the platform resulting from the bouncing specimen shall be negligible. This
can be achieved by sufficient strength and stiffness of the supporting stiff frame.
If prescribed by the relevant specification, other kinds of motion can be used that require
special bounce testing machines, such as circulating (see A.3.1) or non-synchronous (A.3.2)
motion of the platform.
– 8 – 60068-2-55 © IEC:2013
4.4 Tolerances on the horizontal accuracy of platform
The testing machine shall be installed so that at its lowest point (bottom dead centre of the
motion), the platform is horizontal within the following tolerance:
– ±0,5° in the longitudinal and lateral axes (respectively pitching and rolling angles).
Any allowances for play of the drive mechanism are included in this value.
4.5 Control
The motion of the platform is controlled. Acceleration or displacement control is permissible. If
the platform is driven mechanically by eccentrics, actual eccentricity and control of the shaft
speed may be used. It is not necessary to measure the response of the specimen.
The impacts of the specimen on the platform are very likely to influence the actual motion of
the platform. The occurrence of high-frequency oscillations resulting from these impacts shall
be considered, as this may lead to signal distortion without appropriate filtering. In the case of
the reference point being influenced by the impacting, and the stated tolerances not being
able to be met, the achieved result shall be stated in the test report.
4.6 Mounting
For the purpose of this test, the specimen is never fastened or otherwise fixed to the platform
during testing.
4.7 Horizontal motion of specimen
The horizontal motion of the specimen shall be limited by suitable barriers of sufficient
strength and stiffness.
The maximum horizontal clearance shall be small compared to the size of the specimen but
large enough to allow for free vertical movement. Normally, this is achieved by a clearance of
approximately 10 mm on each side.
A suitable barrier arrangement is described in Clause A.2 and shown in Figure A.1.
5 Severities
NOTE Severity is described by the motion of the platform and the testing duration.
5.1 Severity for sinusoidal motion of the platform
If sinusoidal vibration is required, the relevant specification should refer to IEC 60068-2-6 and
prescribe the amplitude and frequency of the motion together with the testing duration.
The duration of testing shall be selected from the severities given below. These severities
represent the nominal duration of testing, exclusive of recovery periods (see Clause 8), to be
applied. The test duration depends on the specimen and the purpose of the test:
– 180 min;
–  90 min;
–  60 min;
–  15 min;
–   5 min.
The duration of testing shall be divided equally between the specified attitudes or as required
by the relevant specification, see Clause 8.

60068-2-55 © IEC:2013 – 9 –
The following values are often applied:
Sinusoidal motion of the platform according to IEC 60068-2-6, peak displacement amplitude
of 12,75 mm ±0,5 mm at a frequency of 4,75 Hz ±0,05 Hz. This is equivalent to a peak
acceleration amplitude of approximately 1,1 g . A typical test duration for robustness testing
n
of shipping containers is 60 min.
NOTE The test severity given here corresponds to widely used test procedures. However, it is considered as very
conservative and not related to the operational or transportation environment.
5.2 Severity for random motion of the platform
If random vibration is required, the relevant specification should refer to IEC 60068-2-64 and
prescribe the ASD spectrum of the motion together with the test duration.
The duration of testing shall be divided equally between the specified attitudes or as required
by the relevant specification, see Clause 8.
5.3 Severity for mixed mode motion of the platform
If mixed mode vibration is required, the relevant specification should refer to IEC 60068-2-80
and prescribe the mixed mode spectrum of the motion together with the test duration.
NOTE 1 Mixed mode produces a stochastic bouncing of packaged specimens. Digital vibration control systems
require long loop times at these low frequencies and it may be some time before the test starts and equalization is
achieved.
NOTE 2 Bouncing motion generated with a pure random or pure sine vibration is unsuitable for reproducing the
motion required for unfixed packaged specimens.
5.4 Severity for use of special bounce testing machines
If the relevant specification requires use of a special bounce testing machine (see Clause A.3),

the kind of motion and the testing duration shall be specified.
6 Preconditioning
If the relevant specification calls for preconditioning it shall then prescribe the conditions.
7 Initial measurements and functional performance test
The specimen shall be submitted to visual, dimensional, functional and any other checks as
prescribed by the relevant specification.
8 Testing
The specimen, with or without its transport case or packaging as required by the relevant
specification, is placed in the middle of the platform without being fixed.
A vibration test is carried out with an excitation as prescribed by the test severity (see
Clause 5).
One or several points on the platform not reached by the bouncing specimen is/are chosen as
reference points. If necessary, multi-point control may be used, provided that this is stated in
the test report. However, it is only expected to use multi-point control for very large, heavy
equipment. In that case, the reference points shall be located on each side of the specimen
on the platform. No additional check points are required.

– 10 – 60068-2-55 © IEC:2013
In case of sinusoidal motion of the platform, IEC 60068-2-6 applies, in case of random motion,
IEC 60068-2-64 applies. The requirements of the respective standards shall be fulfilled for the
reference points on the platform.
NOTE 1 The vibration testing standards IEC 60068-2-6 and IEC 60068-2-64 impose additional uniformity
requirements on multiple check points that are not applicable for bounce tests according to this standard.
The test may be interrupted for inspection of the specimen, or to prevent excessive
temperature rises, provided that the testing duration is properly achieved.
NOTE 2 Excessive temperature rises may occur in specimens which contain highly resilient structures or parts,
except possibly for the severity of 5 min. In such cases it may be necessary, in order to prevent an excessive
temperature rise within the specimen, to carry out the test in a series of phases (each of, say, 5 min bouncing
followed by a recovery period of 5 min or longer) as required by the relevant specification.
If pre-tests are necessary for adjustment of the testing machine, this time shall not be
deducted from the test duration.
Where the aspect ratio of the specimen (the ratio of its longest side to its shortest) does not
exceed 3:1 and the mass does not exceed 50 kg, the specimen shall be subjected to bounce
on each of its attitudes (for example the two bases and the lateral surface for a cylinder and
six sides for a rectangular (parallelepipedal) object).
For specimens of greater mass or aspect ratio, or of a different form, the test shall be carried
out as required by the relevant specification.
In this case, it can be necessary to further constrain the horizontal and overturning movement
of the specimen. The vertical movement should not be restrained. The measures used for
constraining movement should be stated in the test report.
Where there is only a limited number of faces on which the specimen would be transported,
the relevant specification shall state the attitude(s) of the specimen for the test (see
Clause A.5) and the test duration to be applied to each attitude.
If required by the relevant specification, specimens of any aspect ratio may be stacked,
provided that the overall height does not exceed 600 mm. The relevant specification shall
state what special arrangements, if any, are needed to constrain the movement of the topmost
specimen.
Special bounce testing machines designed for circular or non-synchronous motion of the
platform may be used for testing if prescribed by the relevant specification. Test procedures
for these cases are described in Clause A.3.
9 Recovery
It is sometimes necessary to provide a period of time after testing and before final
measurements in order to allow the specimen to attain the same conditions, for example of
temperature, as existed for the initial measurements. The relevant specification shall then
prescribe the conditions for recovery.
10 Final measurements
The specimen shall be submitted to visual, dimensional and functional checks and any others
as prescribed by the relevant specification.
The relevant specification shall provide the criteria upon which the acceptance or rejection of
the specimen shall be based.
60068-2-55 © IEC:2013 – 11 –
11 Information to be given in the relevant specification
When this test is included in a relevant specification, the following details shall be given as far
as they are applicable:
Clause and
subclause
a) Acceptance and rejection criteria (see Clause A.7) 2
b) Test method, motion of the platform, (see Clause A.3)  4
c) Severity (see Clause A.4) 5
d) Preconditioning 6
e) Initial measurements (see Clause A.7) 7
f) Testing with or without transport case 8
g) Attitude and orientation of specimen, distribution of test duration
on different attitudes (see Clause A.5) 8
h) Stacking requirements (see Clause A.6) 8
i) Final measurements (see Clause A.7) 9
12 Information to be given in the test report
As a minimum, the test report shall show the following information:
1. Customer (name and address)
2. Test laboratory (name and address)
3. Test report identification (date of issue, unique number)
4. Test dates
5. Purpose of the test (development test, qualification)
6. Test standard, edition (relevant test procedure)
7. Test specimen description (unique identity, drawing, photo, quantity,
comments on initial status of testspecimen,
etc.)
8. Test apparatus (motion, description of the platform and barriers)
9. Excitation axis (testing attitude and testing axes)
10. Measuring system, sensor location, filters (description, drawing, photo)
11. Uncertainties of measuring system (calibration data, last and next date)
12. Initial, intermediate or final measurements
13. Required severities (from test specification)
14. Test severities with documentation (measurements at reference points, test
durations for different attitudes)
15. Test results (comment on status of test specimen)
16. Observations during testing and actions taken
17. Summary of test
18. Test manager (name and signature)
19. Distribution (list of those receiving report)
NOTE 1 A test log should be written to document, for example, a chronological list of test runs with test
parameters, observations during testing and actions taken and data sheets on measurements made. The test log
can be attached to the test report.
NOTE 2 See also ISO/IEC 17025.

– 12 – 60068-2-55 © IEC:2013
Annex A
(normative)
Guidance
A.1 General
Specimens carried as loose cargo by overland transport can be subjected to severe and
repetitive shock from impacting, rebounding and scuffing on the floor of the transporting
vehicle or from colliding with the side walls of the vehicle or other cargo. Even when tied to
the vehicle platform they can be subject to similar shock if the constraint allows freedom of
movement.
The severity of the shock depends upon the location in the vehicle, the type of surface being
traversed (for example, a pot-holed road, an off-the-road terrain), the accumulated duration of
transportation and, in particular, the dynamic characteristics of the specimen. A specimen
having a high degree of resilience will rebound on impact with the vehicle platform and is
more likely to collide with side walls and other cargo. A non-resilient specimen would tend
more to remain in close contact with the platform and would not normally be subjected to such
severe impact.
The bounce test fulfils a similar function to the shock test (see also Annex B) but since the
specimen is not fastened to the test platform, it more closely simulates the stress resulting
from impact and shock to which the specimen would be subjected when carried loose in a
vehicle (see A.7.2).
In particular for low resonance frequencies of the specimen, re-excitation of the specimen
before the natural response has decayed away may give varying results for identical
specimens.
NOTE In order to assess whether the conditions stated have been satisfied, the test engineer may make use of
the following formula which is not intended for general use and should not be referred to in specifications:
R = f /10  (A.1)
res min
where R is the repetition rate (bounces per second) and fres min is the lowest resonance frequency.
A.2 Barrier arrangement (see 4.6)
To prevent the specimen from falling off the platform, barriers need to be constructed on the
platform of the testing machine.
The horizontal clearance shall be adjusted to the size of the specimen. It should be as small
as possible, normally not exceeding 5 % of the specimen size, although for the methods
provided in Clause A.3, a specified clearance applies. However, the barriers shall allow for
free vertical movement of the specimen. Under normal circumstances this can be achieved by
a clearance of approximately 10 mm on each side.
The vertical height of the barriers shall be at least 60 % of the height of the specimen to
prevent toppling. In some cases (specimens with a high centre of gravity) higher barriers are
required.
If one of the two test methods provided in Clause A.3 is to be used, the barriers are also used
to simulate the impact of the specimen with the sides of a vehicle. For this purpose, higher
strength and stiffness is necessary. The barriers should be constructed with the specified
clearance and be of timber walls, timber faced steel or square sectioned timber. A typical
barrier arrangement is shown in Figure A.1.

60068-2-55 © IEC:2013 – 13 –
IEC  388/13
Key
Reference point
Figure A.1 – Typical arrangement of barriers and typical reference point positions
A.3 Test apparatus (Clause 4)
A.3.1 General
Normally, this test can be carried out using a shaker table and a platform attached to it that
meets the characteristics given in 4.1.
Additionally, two methods of carrying out the bounce test are given in this standard that
require special bounce testing machines, capable of operating in two distinct modes. The
relevant specification shall explicitly state if one of these is to be applied.
Method A gives a circular motion of amplitude and speed sufficient to produce an acceleration
in excess of 1 g in the vertical plane. The vertical motion induces bounce and the horizontal
n
motion induces occasional impact with the barrier rails.
Method B is based on a non-synchronous vertical motion of the platform in which two drive
points (see Figure A.2) are driven at different speeds. This results in a motion which
progressively changes from linear vertical to pitching; the vertical motion induces bouncing,
the pitching motion impact with the barrier rails. A mechanism which will produce the motion
required for this method is shown in Figure A.2.
NOTE The facilities used for these test methods are considered technically outdated and not suitable for any
other purposes than this particular test. They do not allow enough flexibility for test tailoring. However, they provide
comparatively simple means for conducting bounce tests.

– 14 – 60068-2-55 © IEC:2013
Dimensions in millimetres
B
C
D
A
IEC  389/13
Dimensions:
600 ≤ A ≤ 1 700
B ≥ 250
C = 0,25 A ±5 %
D = 0,08 A ±5 %
where A is the distance between the drive points.
Figure A.2 – Basic drive motion of a mechanical bounce tester
A.3.2 Method A: Synchronous circular motion
The motion of the platform of the bounce tester shall be such that each point of this platform
describes a circle in the vertical plane with a diameter of 25,5 mm ±0,5 mm (see 4.3).
The peak acceleration of the platform shall be between 1,1 g and 1,2 g . This can be
n n
–1
achieved with a platform driven by eccentrics at a mean shaft rotation speed of (285 ±3) min .
The specimen prepared as for transportation, with or without its transport case as prescribed
by the relevant specification, shall be placed, without being attached, on the platform centrally
between the drive shafts.
The horizontal motion shall be limited by suitable wooden barriers that are periodically
impacted by the specimen. These barriers shall simulate the resilient properties of pinewood
board 50 mm in thickness.
The horizontal motion of the specimen allowed by the barriers shall be adjusted to a total of
50 mm ±5 mm, that is, the specimen when placed at the centre of the platform in its normal
position, shall have a free movement in any horizontal direction of a nominal 25 mm (see 4.6).
The top edge of the barrier shall be not more than 600 mm above the platform and shall be at
least at the height of the specimen.
A suitable barrier arrangement is described in Clause A.2 and shown in Figure A.1.
A.3.3 Method B: Non-synchronous motion
The motion of the platform shall vary cyclically between a linear vertical and a pitching motion.
This motion is produced by a nominally vertical drive applied to the platform along two
transverse lines spaced not less than 600 mm nor more than 1 700 mm apart, see Figure A.2.

60068-2-55 © IEC:2013 – 15 –
The applied peak-to-peak value of the displacement at the drive points on the platform shall
be 25,5 mm ±0,5 mm.
The frequencies at the two drive points shall be related in the ratio 1 to 0,9 with a tolerance of
–1
±0,03: the higher-speed drive shaft shall rotate at a mean speed of (285 ±5) min .
In the direction transverse to the required motion, the displacement shall be, in principle, zero
except for the effects of play in the drive mechanism.
The distance between the drive points on the platform shall normally be greater than the
longest base dimension of the specimen undergoing test and the size of the test facility shall
be chosen accordingly.
NOTE When there is no facility fully satisfying the requirements, the available facility may be used, provided that
this is stated in the test report.
The specimen prepared as for transportation, with or without its transport case as prescribed
by the relevant specification, shall be placed, without being attached, on the platform centrally
between the drive points.
The horizontal motion shall be limited by suitable wooden barriers that are periodically
impacted by the specimen. These barriers shall simulate the resilient properties of pinewood
board 50 mm in thickness.
The horizontal motion allowed by the barriers shall be adjusted to a total of between 100 mm
and 150 mm, that is the specimen, when placed at the centre of the platform in its normal
position, shall have a free movement in any horizontal direction of between 50 mm and 75 mm
(see 4.6).
The top edge of the barrier shall be not more than 600 mm above the platform and it shall be
between 25 mm and 75 mm below the top of the specimen.
A suitable barrier arrangement is described in Clause A.2 and shown in Figure A.1.
A.4 Test severities (Clause 5)
The severity of the bounce test is defined by the motion of the platform and the test duration.
In contrast to vibration testing, the motion of the specimen is not prescribed directly.
However, the methodology and testing standards for vibration testing can be applied, provided
that the shaker table, or the platform attached to it, is controlled and also able to perform the
prescribed motion if loaded by the bouncing specimen. In contrast to vibration testing, the
demands on rigidity and uniformity of motion of the platform are alleviated.
The repetitive shocks resulting from loose cargo testing results in high-frequency noise that
requires appropriate filtering. Therefore, high-frequency excitation is usually not considered.
Moreover, typical excitation frequencies resulting from vehicle vibrations are below
approximately 200 Hz.
Traditionally, loose cargo testing has been carried out with bounce tests using mechanically
driven fixed-amplitude bounce testing machines. They do not provide the flexibility for test
tailoring according to the operational or transport environment.
Loose cargo testing with sinusoidal motion of the platform has similar drawbacks. Its main
purpose is to perform tests similar to the traditional bounce tests with modern test equipment.
The severity proposed for sinusoidal bounce testing in 5.1 has this intention.

– 16 – 60068-2-55 © IEC:2013
In contrast, application of shaped random ASD spectra to random vibration of the platform
allows for test tailoring. However, this requires a spectrum adapted to the particular
transportation environment and a testing duration adapted to the transportation distance.
Standards utilizing a single test spectrum at a fixed duration usually have a conservative
approach based on measurements and experience. The user shall thoroughly check the
transportation environment and distance they cover. However, conservative testing of
products for a multitude of applications will often result in a weight gain of the product or
increased dimensions. The resulting monetary and environmental costs in particular during
transportation should be considered.
If no data is available for the transport chain, standard spectra can be used, see
IEC 60068-2-64, IEC 60721-4-2, ASTM D 4169 or ISO 13355.
A.5 Specimen axes and directions of bounce (Clause 8)
The axes and directions of bounce chosen for the testing of the specimen should be
representative of its attitudes during transportation. Specimens which would always be
transported on a dedicated base need only be subjected to the bounce test when resting on
that base. For a specimen which can be carried resting on more than one of its faces, testing
should be carried out on each face prescribed by the relevant specification.
In the two test methods provided in Clause A.3, to simulate the impact with the sides of the
vehicle platform or with other cargo, the specimen resting on each relevant face needs to be
turned regularly, several times, through 90° in the horizontal plane during the test so that the
impact with the barriers of the test machine is applied to each vertical face.
A.6 Stacked specimens (Clause 8)
When items are stacked in a vehicle, there can be significant differences between the
environments experienced by the top and bottom layers. It is the transport case of a specimen
which is most vulnerable when it is in the bottom layer, whilst in the top layer it is the contents
of the transport case. In these circumstances it may be necessary to vary the positions of the
specimens in the stack.
Also, a dummy load may be applied to simulate the influence of the upper layers.
A.7 Functional checks (Clauses 7 and 9)
A.7.1 Components and equipment
Damage to specimens, although it may be detected as change in performance, is usually of a
mechanical nature such as loosening of screws and failure of mechanical parts and/or
connections. At the completion of the test, particular attention should be given to this type of
damage and its probable effect on performance.
A.7.2 Specimens including transport cases or packaging
In evaluating the performance of specimens which includes the transport case or packaged
...