ISO 5348:2021
(Main)Mechanical vibration and shock — Mechanical mounting of accelerometers
Mechanical vibration and shock — Mechanical mounting of accelerometers
This document specifies the important technical properties of the different methods for mounting vibration transducers and describes recommended practices. It also shows examples of how accelerometer mounting can influence frequency response and gives examples of how other influences can affect the fidelity of the representation of actual motion in the structure being observed. This document applies to the contacting type of accelerometer which is currently in wide use. It is applicable to both uniaxial and multi-axial transducers. This document can also be applied to velocity transducers. This document enables the user to estimate the limitations of a mounting and consequent potential measurement deviations. Transducer mounting issues are not the only problem that can affect the validity of acceleration measurement. Other such problems include, amongst others: transverse movements, alignment of the transducer, base bending, cable movement, temperature changes, electric and magnetic fields, cable whip and mounting torque. Issues other than mounting and their possible effects are outside the scope of this document.
Vibrations et chocs mécaniques — Fixation mécanique des accéléromètres
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INTERNATIONAL ISO
STANDARD 5348
Third edition
2021-01
Mechanical vibration and
shock — Mechanical mounting of
accelerometers
Vibrations et chocs mécaniques — Fixation mécanique des
accéléromètres
Reference number
©
ISO 2021
© ISO 2021
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ii © ISO 2021 – All rights reserved
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Basics . 1
5 Characteristics to be specified by manufacturers of accelerometers .4
6 Considerations for selecting a mounting method . 4
6.1 General considerations . 4
6.1.1 Procedures . 4
6.1.2 Conditions . 4
6.2 Specific considerations . 5
6.2.1 Frequency range of operation . 5
6.2.2 Transducer cable . 5
6.3 Determination of the mounted fundamental resonance frequency. 6
6.3.1 General. 6
6.3.2 Vibration excitation method . 6
6.3.3 Shock excitation methods . 7
6.4 Recommendations for particular types of mountings . 8
6.4.1 General. 8
6.4.2 Stud mounting . 9
6.4.3 Adhesive mounting .10
6.4.4 Magnets .13
6.4.5 Quick mount.13
6.4.6 Probe .14
6.4.7 Conical bolting .14
6.4.8 Low-percussion mounting devices for recording human exposure to vibration .15
6.4.9 Mounting by three-point support and ground spikes.15
6.4.10 Wedge anchors .15
6.4.11 Mounting fixtures .15
7 Typical frequency response for various types of mounting .16
8 Further mounting aspects .19
8.1 Base strain sensitivity of an accelerometer .19
8.2 Thermal mounting effects .19
8.3 Electrical ground loops .20
Bibliography .21
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
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expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www .iso .org/
iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 108, Mechanical vibration, shock and
condition monitoring.
This third edition cancels and replaces the second edition (ISO 5348:1998), which has been technically
revised.
The main changes compared to the previous edition are as follows:
— the theory of mass and stiffness influence on the frequency response obtained has been expanded;
— the frequency responses have been replaced by actual measurements and have been made more
comparable;
— the influence of electrical loops has been added.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
iv © ISO 2021 – All rights reserved
Introduction
The method most commonly used for determining the vibratory motion of a structure or body is
the use of an electromechanical vibration transducer, also called a transducer or a vibration sensor.
These vibration transducers can be divided into the two broad classes: non-contacting and contacting
transducers.
Non-contacting transducers are relative measuring transducers recording a motion in relation to a
fixed space coordinate system. Typical examples are eddy-current probes, optical sensors and laser
vibrometers. These transducers have no direct mechanical contact with the structure and are therefore
not dealt with in this document.
Contacting transducers are mounted onto the structure by mechanical coupling. This includes, for
example, piezoelectric, capacitive and piezoresistive accelerometers as well as seismic velocity
transducers. These absolute measuring transducers record the motion by seismic forces from the space
coordinate system onto which they are mounted. If such a transducer is mounted onto a structure, the
properties of the mounting can significantly influence the frequency response of the structure as well
as the vibration transducer. Very large measurement deviations can occur in case of lack of care in the
mounting property, particularly at high frequencies.
Under certain circumstances the mass, geometry and mounting stiffness of the transducer can directly
influence the measured vibration amplitude of the structure. This effect occurs for example if the
masses of the transducer and the structure are in the same order of magnitude.
This document is concerned with the contacting type of seismic accelerometers and seismic velocity
transducers which are currently in wide use. The concern with using such transducers is that the
mechanical coupling between the accelerometer and the test structure can significantly alter the
response of the accelerometer, the structure or both. This document attempts to isolate parameters of
concern in the selection of a method to mount the accelerometer onto the structure.
In a basic sense, many aspects of velocity transducer mounting are similar to those of accelerometers,
but they are not identical. Please refer to 6.2.1.
This document does not cover geophones.
INTERNATIONAL STANDARD ISO 5348:2021(E)
Mechanical vibration and shock — Mechanical mounting of
accelerometers
1 Scope
This document specifies the important technical properties of the different methods for mounting
vibration transducers and describes recommended practices. It also shows examples of how
accelerometer mounting can influence frequency response and gives examples of how other influences
can affect the fidelity of the representation of actual motion in the structure being observed.
This document applies to the contacting type of accelerometer which is currently in wide use. It is
applicable to both uniaxial and multi-axial transducers. This document can also be applied to velocity
transducers.
This document enables the user to estimate the limitations of a mounting and consequent potential
measurement deviations.
Transducer mounting issues are not the only problem that can affect the validity of acceleration
measurement. Other such problems include, amongst others: transverse movements, alignment of the
transducer, base bending, cable movement, temperature changes, electric and magnetic fields, cable
whip and mounting torque. Issues other than mounting and their possible effects are outside the scope
of this document.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 2041, Mechanical vibration, shock and condition monitoring — Vocabulary
ISO 8042, Shock and vibration measurements — Characteristics to be specified for seismic pick-ups
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 2041 apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedi
...
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