This part of ISO 16063 specifies the instrumentation and procedures used for primary angular vibration
calibration of angular transducers, i.e. angular accelerometers, angular velocity transducers and rotational
angle transducers (with or without amplifier) to obtain the magnitude and the phase shift of the complex
sensitivity by steady-state sinusoidal vibration and laser interferometry. The methods specified in this part of
ISO 16063 are applicable to measuring instruments (rotational laser vibrometers in particular) and to angular
transducers as defined in ISO 2041 for the quantities of rotational angle, angular velocity and angular
acceleration.
It is applicable to a frequency range from 1 Hz to 1,6 kHz and a dynamic range (amplitude) from 0,1 rad/s2 to
1 000 rad/s2 (frequency-dependent).
These ranges are covered with the uncertainty of measurement specified in Clause 3. Calibration frequencies
lower than 1 Hz (e.g. 0,4 Hz, which is a reference frequency used in other International Standards) and
angular acceleration amplitudes smaller than 0,1 rad/s2 can be achieved using method 3A or method 3B
specified in this part of ISO 16063, in conjunction with an appropriate low-frequency angular vibration
generator.
Method 1A (cf. Clause 8: fringe-counting, interferometer type A) and method 1B (cf. Clause 8: fringe-counting,
interferometer type B) are applicable to the calibration of the magnitude of complex sensitivity in the frequency
range of 1 Hz to 800 Hz and under special conditions, at higher frequencies. Method 2A (cf. Clause 9:
minimum-point method, interferometer type A) and method 2B (cf. Clause 9: minimum-point method,
interferometer type B) can be used for sensitivity magnitude calibration in the frequency range of 800 Hz to
1,6 kHz. Method 3A (cf. Clause 10: sine-approximation method, interferometer type A) and method 3B
(cf. Clause 10: sine-approximation method, interferometer type B) can be used for magnitude of sensitivity
and phase calibration in the frequency range of 1 Hz to 1,6 kHz. Methods 1A, 1B and 3A, 3B provide for
calibrations at fixed angular acceleration amplitudes at various frequencies. Methods 2A and 2B require
calibrations at fixed rotational angle amplitudes (angular velocity amplitude and angular acceleration
amplitude vary with frequency).
NOTE 1 The numbering 1 to 3 of the methods characterizes the handling of the interferometer output signal(s)
analogous to ISO 16063-11: number 1 for fringe counting, number 2 for minimum-point detection and number 3 for sineapproximation.
Each of these signal handling procedures can be used together with interferometer types A and B specified
in this part of ISO 16063.
Interferometer type A designates a Michelson or Mach-Zehnder interferometer with retro-reflector(s) located at a radius, R,
from the axis of rotation of the angular exciter. This interferometer type is limited to rotational angle amplitudes of 3°
maximum. Interferometer type B designates a Michelson or a Mach-Zehnder interferometer using a circular diffraction
grating implemented on the lateral surface of the circular measuring table. This interferometer type is not limited as
regards the rotational angle amplitude if the diffraction grating covers the whole lateral surface of the disk (i.e. 360°).
Usually, the maximum angular vibration is, in this case, limited by the angular vibration exciter.
NOTE 2 Though the calibration methods specified in this part of ISO 16063 are applicable to angular transducers
(according to definition in ISO 2041) and, in addition, to measuring instrumentation for angular motion quantities, the
specifications are given for transducers as calibration objects, for the sake of simplified description. Some specific
information for the calibration of rotational laser vibrometers is given in 4.11 and Figure 11.