BS ISO 16063-41:2011

Foreword
1 Scope
2 Normative references
3 Classification of laser vibrometers and principles of test
   methods
4 Uncertainty of measurement
5 Requirements for apparatus and other conditions
6 Preferred amplitudes and frequencies
7 Common procedure for primary calibration (methods 1, 2
   and 3)
8 Method using fringe counting (method 1)
9 Method using minimum-point detection (method 2)
10 Methods using sine approximation: method 3 (homodyne
   version) and method 3 (heterodyne version)
11 Method using comparison to a reference transducer (method 4)
12 Report of calibration results
Annex A (normative) - Uncertainty components in the primary
        calibration by laser interferometry of vibration and
        shock transducers
Annex B (informative) - Three versions of method 3 based on
        laser Doppler velocimetry
Annex C (informative) - Example of calculation of measurement
        uncertainty in calibration of a laser vibrometer
Annex D (informative) - Phase shift calibration of laser
        vibrometers
Bibliography

Describes the instrumentation and procedures for performing primary and secondary calibrations of rectilinear laser vibrometers in the frequency range typically between 0,4 Hz and 50 kHz.

This part of ISO16063 specifies the instrumentation and procedures for performing primary and secondary calibrations of rectilinear laser vibrometers in the frequency range typically between 0,4Hz and 50kHz. It specifies the calibration of laser vibrometer standards designated for the calibration of either laser vibrometers or mechanical vibration transducers in accredited or non-accredited calibration laboratories, as well as the calibration of laser vibrometers by a laser vibrometer standard or by comparison to a reference transducer calibrated by laser interferometry. The specification of the instrumentation contains requirements on laser vibrometer standards.

Rectilinear laser vibrometers can be calibrated in accordance with this part of ISO16063 if they are designed as laser optical transducers with, or without, an indicating instrument to sense the motion quantities of displacement or velocity, and to transform them into proportional (i.e. time-dependent) electrical output signals. These output signals are typically digital for laser vibrometer standards and usually analogue for laser vibrometers. The output signal or the reading of a laser vibrometer can be the amplitude and, in addition, occasionally the phase shift of the motion quantity (acceleration included). In this part of ISO16063, the calibration of the modulus of complex sensitivity is explicitly specified (phase calibration is provided in AnnexD).

NOTE Laser vibrometers are available for measuring vibrations having frequencies in the megahertz and gigahertz ranges. To date, vibration exciters are not available for generating such high frequencies. The calibration of these laser vibrometers can be estimated by the electrical calibration of their signal processing subsystems utilizing appropriate synthetic Doppler signals under the following preconditions:

• the optical subsystem of the laser vibrometer to be calibrated has been proven to comply with defined requirements comparable to those given in 5.5.3;

• synthetic Doppler signals are generated as an equivalent substitute for the output of the photodetectors.

More detailed specifications of this approach (see Reference [25]) lie outside the scope of this part of ISO16063.