ISO 16063-21:2003

INTERNATIONAL ISO
STANDARD 16063-21
First edition
2003-08-15
Methods for the calibration of vibration
and shock transducers —
Part 21:
Vibration calibration by comparison to a
reference transducer
Méthodes pour l'étalonnage des transducteurs de vibrations et de
chocs —
Partie 21: Étalonnage de vibrations par comparaison à un transducteur
de référence
Reference number
©
ISO 2003
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ii © ISO 2003 — All rights reserved

Contents Page
Foreword. iv
Introduction . v
1 Scope. 1
2 Normative references . 1
3 Uncertainty of measurement. 2
4 Requirements for apparatus and environmental conditions. 3
4.1 General. 3
4.2 Environmental conditions. 3
4.3 Reference transducer . 3
4.4 Vibration generation equipment. 4
4.5 Voltage measuring instrumentation. 6
4.6 Distortion measuring instrumentation. 6
4.7 Oscilloscope. 7
4.8 Phase shift measuring instrumentation . 7
5 Calibration. 7
5.1 Preferred amplitudes and frequencies . 7
5.2 Measurement requirements . 7
5.3 Calibration procedure. 8
6 Expression of results. 8
7 Reporting the calibration results. 9
Annex A (normative) Expression of uncertainty of measurement in calibration . 11
Annex B (normative) Definitions of amplitude sign and phase shift between mechanical motion
and vibration transducer electrical output. 20
Annex C (informative) Nomogram for conversion between acceleration, velocity and
displacement . 22
Annex D (informative) Example of uncertainty calculation. 24
Bibliography . 29

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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
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.
ISO 16063-21 was prepared by Technical Committee ISO/TC 108, Mechanical vibration and shock,
Subcommittee SC 3, Use and calibration of vibration and shock measuring instruments.
This first edition of ISO 16063-21 cancels and replaces ISO 5347-3:1993, which has been technically revised.
ISO 16063 consists of the following parts, under the general title Methods for the calibration of vibration and
shock transducers:
— Part 1: Basic concepts
— Part 11: Primary vibration calibration by laser interferometry
— Part 12: Primary vibration calibration by the reciprocity method
— Part 13: Primary shock calibration using laser interferometry
— Part 21: Vibration calibration by comparison to a reference transducer
— Part 22: Shock calibration by comparison to an accelerometer, velocity or force transducer
iv © ISO 2003 — All rights reserved

Introduction
The ISO 16063 series of standards is concerned with methods for the calibration of vibration and shock
transducers under both standard laboratory conditions and in the field.
As such, the intended user group of this part of ISO 16063 is wide, ranging from metrologists in mechanical
vibration to technicians evaluating the vibration characteristics of a machine or structure, or human exposure
to vibration. The key to the application of this part of ISO 16063 is in the careful detailed specification and
evaluation of measurement uncertainty, i.e. the error budget and computation of expanded uncertainty
associated with the measurement of vibration.
This part of ISO 16063 is particularly intended for those engaged in vibration measurements requiring
traceability to primary national or international standards through a secondary, reference, working or check
standard (portable calibrator intended for field use) as defined in the International vocabulary of basic and
general terms in metrology (VIM). The specifications for the instrumentation and the procedures given are
intended to be used for calibration of rectilinear vibration transducers (with or without signal conditioning) to
obtain the magnitude and (optionally) phase shift of the complex sensitivity at frequencies in the range of
0,4 Hz to 10 kHz.
INTERNATIONAL STANDARD ISO 16063-21:2003(E)

Methods for the calibration of vibration and shock
transducers —
Part 21:
Vibration calibration by comparison to a reference transducer
1 Scope
This part of ISO 16063 describes the calibration of rectilinear vibration transducers by comparison. Although it
mainly describes calibration using direct comparison to a standard calibrated by primary methods, the
methods described can be applied between other levels in the calibration hierarchy.
This part of ISO 16063 specifies procedures for performing calibrations of rectilinear vibration transducers by
comparison in the frequency range from 0,4 Hz to 10 kHz. It is primarily intended for those who are required to
meet ISO standardized methods for the measurement of vibration under laboratory conditions, where the
uncertainty of measurement is relatively small. It can also be used under field conditions, where the
uncertainty of measurement may be relatively large.
From knowledge of all significant sources of uncertainty affecting the calibration, the expanded uncertainty
can be evaluated using the methods given in this part of ISO 16063. It also covers the assessment of
uncertainties for calibrations performed using a check standard.
Comparison calibrations made in accordance with this part of ISO 16063 need to allow for the environmental
conditions of the reference transducer calibration.
NOTE Transducer calibrations made under extreme environmental conditions are covered by other International
Standards.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO 266, Acoustics — Preferred frequencies
ISO 2041:1990, Vibration and shock — Vocabulary
ISO 16063-1:1998, Methods for the calibration of vibration and shock transducers — Part 1: Basic concepts
ISO 16063-11:1999, Methods for the calibration of vibration and shock transducers — Part 11: Primary
vibration calibration by laser interferometry
Guide to the expression of uncertainty in measurement (GUM). BIPM, IEC, IFCC, ISO, IUPAC, IUPAP, OIML,
1)
1) Corrected and reprinted in 1995.
3 Uncertainty of measurement
3.1 All users of this part of ISO 16063 are expected to make uncertainty budgets according to Annex A to
document their level of uncertainty (see example in Annex D).
To help set up systems fulfilling different requirements two examples are given. System requirements for each
are set up and the attainable uncertainty is given. Example 1 is typical for calibrations under well-controlled
laboratory conditions with the requirement to obtain a high accuracy. Example 2 is typical for calibrations
where less than the highest accuracy can be accepted or where calibration conditions are such that only less
narrow tolerances can be maintained. These two examples will be used throughout this part of ISO 16063.
a) Example 1
The reference transducer is calibrated by primary means and documented uncertainty. The calibration
may be transferred to a working standard for practical reasons. The temperature and other conditions are
kept within narrow limits during the comparison calibration as indicated in the appropriate clauses.
b) Example 2
The reference transducer is not calibrated by primary means, but has a traceable calibration, as defined
in VIM (see [2]), with the corresponding uncertainty documented. The calibration may be transferred to a
working standard for practical reasons. The requirements on other parameters and instruments are
indicated in the appropriate clauses.
3.2 For both examples, the minimum calibration requirement for the reference transducer is calibration
under suitable reference conditions (i.e. frequency, amplitude and temperature). Normally the conditions will
be chosen as indicated in ISO 16063-11.
It is applicable for the following parameters:
Frequency range: 20 Hz to 5 000 Hz, optionally 0,4 Hz to 10 000 Hz (see Note 1)
2 2 2 2
Dynamic range: 10 m/s to 1 000 m/s r.m.s., optionally 0,1 m/s to 1 000 m/s
(frequency dependent)
NOTE The indicated frequency ranges are not mandatory and single-point calibrations are also acceptable.
At any given frequency and amplitude of acceleration, velocity or displacement, the dynamic range will be
limited by the noise floor and the amount of distortion produced by the excitation apparatus (if no filtering is
used) or its maximum power. (Techniques are also used to counteract the inherent distortion at large
displacements for spring-controlled exciters by changing the waveform of the input voltage.) Typical maximum
values for electrodynamic vibration exciters designed for the frequency range from 10 Hz to 10 kHz are
2 2
200 m/s to 1000 m/s r.m.s. acceleration, 0,5 m/s to 1 m/s r.m.s. velocity and 5 mm peak displacement. The
lower limits will be set by the noise in the two measurement channels, and by the bandwidth used. Typical
2 2
values used for measuremen
...