BS 5652:1979

National foreword
Cooperating organizations
List of symbols
1 Scope
2 Purposes
3 Definitions
3.1 Free field
3.2 Far field
3.3 Acoustic centre
3.4 Hydrophone
3.5 Underwater sound projector
3.6 Reversible transducer
3.7 Reciprocal transducer
3.8 Open-circuit voltage at hydrophone
3.9 Free-field sensitivity of a hydrophone
3.10 Pressure sensitivity of a hydrophone
3.11 Transmitting response to a current of a projector
3.12 Electrical terminals of a reciprocal transducer
3.13 Electrical impedance of a transducer
3.14 Electrical transfer impedance magnitude of a
      transducer pair
3.15 Pistonphone
3.16 Vibrating column
3.17 Equivalent noise pressure
3.18 Dynamic range
3.19 Directional response
3.20 Principal axis
3.21 Omnidirectionality
3.22 Types of directional transducers
3.23 Co-ordinate system
4 Procedures for calibration
4.1 Principles
4.2 Field limitations
4.3 Schematic survey of procedures
5 Preparation of the transducers
5.1 Wetting
5.2 Hydrophone support
5.3 Influence of the cable
6 Electrical measurements
6.1 Signal type
6.2 Earthing
6.3 Measurement of hydrophone output voltage
6.4 Measurement of projector current
6.5 Measurement of transfer impedance magnitude
7 Free-field reciprocity calibration
7.1 Scope
7.2 Object
7.3 General principle
7.4 Theory
7.5 Separation distance
7.6 Minimum distance from transducers to boundary
      surfaces
7.7 Signal type
7.8 Frequency limitations
7.9 Measurements
8 Free-field calibration by comparison
8.1 Scope
8.2 Object
8.3 Principle
8.4 Comparison with a standard hydrophone
8.5 Calibration with a calibrated projector
9 Compensation in a closed chamber
9.1 Scope
9.2 Object
9.3 Introduction
9.4 Calibration by electrodynamic compensation
9.5 Calibration by piezoelectric compensation
9.6 Design of the electrodynamic compensation chamber
9.7 Design of the piezoelectric compensation chamber
9.8 Practical limitations of the electrodynamic
      compensation method
9.9 Practical limitations of the piezoelectric
      compensation method
10 Calibration with a pistonphone
10.1 Scope
10.2 Object
10.3 Introduction
10.4 Restrictions
10.5 Sound pressure
10.6 Corrections
10.7 Absolute calibration
10.8 Calibration by comparison
11 Calibration with a vibrating column
11.1 Scope
11.2 Object
11.3 Introduction
11.4 Expression of the sensitivity
11.5 Determination of the sensitivity
11.6 Conditions of measurement
11.7 Accuracy
Appendix A - Measurement of transfer impedance
               magnitude by the substitution method
Appendix B - Measurement of the transfer impedance
               magnitude by the direct read-out method
Appendix C - Pulse technique in free-field calibration
Appendix D - Directional response of a hydrophone
Appendix E - Equivalent circuit of the excitation
               system
Bibliography

Methods for the measurement of the sensitivity of hydrophones, particularly in the frequency range 1 Hz to 1 MHz, and rules for the presentation of the calibration data.