ISO 16063-45:2017

INTERNATIONAL ISO
STANDARD 16063-45
First edition
2017-05
Methods for the calibration of
vibration and shock transducers —
Part 45:
In-situ calibration of transducers with
built in calibration coil
Méthodes pour l’étalonnage des transducteurs de vibrations et de
chocs —
Partie 45: Partie 45: Étalonnage sur site des transducteurs munis
d’une bobine d’étalonnage intégrée
Reference number
ISO 16063-45:2017(E)
©
ISO 2017

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ISO 16063-45:2017(E)

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© ISO 2017, Published in Switzerland
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ISO 16063-45:2017(E)

Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Calibration . 2
4.1 General . 2
4.2 Calibration procedure . 3
4.2.1 General. 3
4.2.2 Calibration in laboratory. 4
4.2.3 In-situ calibration . 4
4.3 Preferred amplitudes and frequencies . 5
5 Uncertainty of measurements . 5
6 Report of calibration results . 7
Annex A (normative) Expression of uncertainty of measurement in calibration .9
Annex B (informative) Example of uncertainty calculation .11
Annex C (informative) Application notices for using this document .16
Bibliography .17
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ISO 16063-45:2017(E)

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
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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
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URL: w w w . i s o .org/ iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 108, Mechanical vibration, shock and
condition monitoring.
A list of all parts in the ISO 16063 series can be found on the ISO website.
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INTERNATIONAL STANDARD ISO 16063-45:2017(E)
Methods for the calibration of vibration and shock
transducers —
Part 45:
In-situ calibration of transducers with built in
calibration coil
1 Scope
This document specifies the calibration of vibration transducers with built-in calibration coils in
laboratory and in situ. In laboratory, the method described can be applied to calibrate the vibration
sensitivity and electrical sensitivity, and to obtain the coefficient of calibration coil. In situ, it can be
used to calibrate the electrical sensitivity and vibration sensitivity using electrical instrumentation.
This document specifies the instrumentation and procedure for performing calibrations of vibration
transducers with built-in calibration coils in the frequency range typically from 0,1 Hz to 100 Hz.
The expanded uncertainty can be evaluated using the method given in 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 16063-1, Methods for the calibration of vibration and shock transducers — Part 1: Basic concepts
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at www .iso .org/ obp
— IEC Electropedia: available at www .electropedia .org
3.1
vibration transducer with built-in calibration coils
vibration transducer employing calibration coils as internal exciting elements for which seismic mass is
excited to vibrate by electromagnetic force produced by the exciting electrical signal of the calibration coil
EXAMPLE 1 Pendulum.
EXAMPLE 2 Seismometers and electromagnetic transducers with built-in calibration coils.
3.2
electrical sensitivity
ratio of the electrical output of the vibration
transducer to the exciting electrical signal of the calibration coil in the absence of mechanical excitation
parallel to a specified axis of sensitivity (3.3) at the mounting surface
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ISO 16063-45:2017(E)

3.3
sensitivity
ratio of the transducer electrical output to its mechanical input during
sinusoidal excitation applied parallel to a specified axis of sensitivity at the mounting surface
3.4
coefficient of calibration coil
ratio of the electrical sensitivity (3.2) to
sensitivity (3.3)
Note 1 to entry: The coefficient of calibration coil is frequency dependent.
4 Calibration
4.1 General
The principle of a vibration transducer with built-in calibration coils is illustrated in Figure 1. The
pendulum vibrates under the inertia force produced by measured vibration. A calibration coil can be
used to produce the equivalent electromagnetic force to simulate the inertial force required to vibrate
the pendulum.
Key
1 pendulum Ue exciting electrical signal of the calibration coil
2 sensing element E output electrical signal of the transducer
3 calibration coil X vibration measured by the transducer
4 measured vibration
Figure 1 — Principle of a vibration transducer with built-in calibration coils
The signals and instrumentations used in the calibration of vibration transducers with built-in
calibration coils are shown in Figure 2.
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ISO 16063-45:2017(E)

Key
1 frequency generator and indicator c coefficient of calibration coil
2 vibration transducer with built-in calibration coils Sv sensitivity
3 voltage measuring instrumentation E output electrical signal of the transducer
Ue exciting electrical signal of the calibration coil X vibration measured by the transducer
Figure 2 — Measuring system for calibration of a vibration transducer with built-in
calibration coils
The electrical sensitivity of the vibration transducer with built-in calibration coils is given in
Formula (1):
E
S = (1)
Ue
The sensitivity of the vibration transducer with built-in calibration coil is given in Formula (2):
E
Sv= (2)
X
The coefficient of calibration coil is given in Formula (3):
S
c= (3)
Sv
According to Formula (1) to Formula (3), the electric sensitivity of the vibration transducer with built-
in calibration coil can described as given in Formula (4):
Sc= Sv (4)
NOTE Further information on the application of calibration coils is given in Annex C.
4.2 Calibration procedure
4.2.1 General
Calibration of vibration transducers with built-in calibration coils comprises two parts: calibration in
laboratory and in-situ calibration.
Before the transducers are employed in situ, calibration can be made in laboratory: the sensitivity
can be calibrated by primary or comparison methods; the electrical sensitivity can be calibrated by
the frequency generator and indicator and voltage measuring instrumentation; and the coefficient of
calibration coil can be calculated according to Formula (3).
After the transducers are employed in situ, the electrical sensitivity can be calibrated by the frequency
generator and indicator and voltage measuring instrumentation and the sensitivity can be calculated
according to Formula (4) using the coefficient of calibration coil obtained in laboratory.
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ISO 16063-45:2017(E)

4.2.2 Calibration in laboratory
4.2.2.1 Calibration of the sensitivity
Determine the sensitivity at the reference frequency ( f ) and acceleration ( X ) using primary or
ref ref
comparison methods. The amplitude of output electrical signal of the transducer is E .
ref
E
ref
Sv =
ref
X
ref
Then, determine the sensitivities at other calibration frequencies and accelerations using primary or
comparison methods.
4.2.2.2 Calibration of the electrical sensitivity
At the reference frequency ( f ), adjust the exciting electrical signal of the calibration coil so that the
ref
amplitude of output electrical signal of the transducer equals E . The amplitude of exciting electrical
ref
signal (Ue ) is being measured simultaneously. The electrical sensitivity at the reference point is
ref
given as follows:
E
ref
S =
ref
Ue
ref
Then, determine the electrical sensitivities at other calibration points using the frequency generator
and indicator and voltage measuring instrumentation.
4.2.2.3 Calibration of the coefficient of calibration coil
The coefficient of calibration coil at the reference point is calculated according to Formula (3):
S
ref
c =
ref
Sv
ref
Then, calculate the coefficient of calibration coil at other calibration points.
4.2.3 In-situ calibration
4.2.3.1 In-situ calibration of the electrical sensitivity
At the reference frequency ( f ), adjust the exciting electrical signal of the calibration coil so that the
ref
amplitude of output electrical signal of the transducer equals E . The amplitude of exciting electrical
ref
signal (Ue ) is being measured simultaneously. The electrical sensitivity at the reference point is
2ref
given as follows:
E
ref
S =
2ref
Ue
2ref
Then, determine the electrical sensitivities at other calibration points using the frequency generator
and indicator and voltage measuring instrumentation.
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ISO 16063-45:2017(E)

4.2.3.2 In-situ calibration of the sensitivity
At the reference point, according to Formula (4), the sensitivity is calculated using the coefficient of
calibration coil calibrated in laboratory.
S
2ref
Sv =
2ref
c
ref
Then, calculate the sensitivities at other calibration points.
4.3 Preferred amplitudes and frequencies
The frequencies, each with associated accelerations, velocities or displacements (amplitude or r.m.s.
value) equally covering the transducer range, should preferably be chosen from the following series.
2
a) Accelerations (m/s ), velocities (m/s) and displacements (mm):
Magnitude values should be selected in 1 – 2 – 5 steps, e.g. 0,01; 0,02; 0,05; 0,1; 0,2; 0,5; 1; 2; 5; 10 …
NOTE The selected amplitudes depend on the measurement type and range of the transducer calibrated.
b) Frequency (Hz):
Selected from the standardized one-third-octave-frequency series (see ISO 266) between 0,1 Hz
and 100 Hz (or the series of radian frequencies evolving from ω = 1 000 rad/s).
5 Uncertainty of measurements
5.1 All users of this document shall make uncertainty budgets in accordance with Annex A to document
their level of uncertainty. An example is given in Annex B.
To help set up systems fulfilling different requirements and environmental conditions, two examples
are given in a) and b) below. For each, system requirements are set up and the attainable uncertainty is
given. These two examples are used throughout this document.
a)  Example 1
The sensitivity is calibrated by primary means and documented uncertainty. In the primary
vibration calibration laboratory, the electrical sensitivity and coefficient of calibration coil are
measured. In situ (for example, cave with seismometers), the electrical sensitivity and sensitivity
are measured. The environmental conditions are well controlled within the limits given in Table 1.
The electrical instrumentations fulfil the requirements given in Table 2 and Table 3.
Table 1 — Environmental conditions for Example 1
Site Parameter Limit
Temperature (23 ± 3) °C
Vibration calibration laboratory Relative humidity 75 % m
...