GB/T 4130.1-2025Acoustics - Calibration of hydrophones - Part 1: Procedures for free-field calibration (English PDF)

Foreword

This document is in accordance with the provisions of GB/T 1.1-2020 "Guidelines for standardization work Part 1: Structure and drafting rules for standardization documents" Drafting.

This document is Part 1 of GB/T 4130 "Calibration of acoustic hydrophones". GB/T 4130 has been published in the following parts.

--- Part 1: Free-field calibration method;

--- Part 2: Low frequency sound pressure field calibration method.

This document replaces GB/T 3223-1994 "Acoustics - Free-field calibration method for underwater acoustic transducers" and is consistent with GB/T 3223-1994.

In addition to structural adjustments and editorial changes, the main technical changes are as follows.

--- Added symbols (see Chapter 4);

--- Added universal calibration steps (see Chapter 5);

--- Added electrical measurements (see Chapter 6);

--- Added transducer preparation (see Chapter 7);

--- Added the report of calibration results (see Chapter 10);

--- Increased recalibration cycle (see Chapter 11);

--- Deleted the determination of hydrophone voltage coupling loss (see Appendix B of the 1994 edition).

This document is equivalent to IEC 60565-1:2020 "Underwater acoustics - Hydrophone calibration - Part 1: Free-field calibration of hydrophones" method".

The following minimal editorial changes have been made to this document.

--- To coordinate with the existing standard, the name of the standard is changed to "Calibration of Acoustic Hydrophones Part 1: Free-field Calibration Method".

Introduction

Hydrophones are used to convert underwater acoustic signals into electrical signals and are the core of sonar, underwater noise measurement systems, marine acoustic instruments and other equipment.

To ensure the accuracy and reliability of their measurement results, they need to be calibrated before use.

GB/T 4130 "Calibration of Acoustic Hydrophones" describes the calibration method of hydrophones, which aims to standardize and guide the calibration of hydrophones.

It consists of parts.

--- Part 1: Free-field calibration method. The purpose is to establish the free-field calibration of hydrophones and transducers in the frequency range of.200 Hz to 1 MHz.

By field calibration method.

--- Part 2: Low frequency sound pressure field calibration method. The purpose is to establish the low frequency sound pressure field calibration method of hydrophone in the frequency range of 0.01 Hz to several kilohertz.

Calibration method in high-frequency sound pressure field.

The purpose of this document is to establish a method for the calibration of hydrophones under free-field conditions for marine applications, including those used as hydrophones and/or transmitters.

This document provides the calibration method for a single underwater electroacoustic transducer with a radiated transducer. This document provides the measurement principles, procedures and sources of uncertainty.

Acoustic hydrophone calibration Part 1: Free-field calibration method

1 Scope

This document specifies the specifications for hydrophones and single electroacoustic transducers that can be used as hydrophones (receivers) and/or transmitters (transmitting transducers).

Free-field calibration methods and procedures. Two general calibration methods are included. absolute calibration using the three-transducer spherical wave reciprocity method;

Relative calibration compared to a calibrated reference device.

The maximum frequency range of the method specified in this document is.200Hz~1MHz. The minimum applicable frequency depends on many factors. Typical the frequency range is.200Hz to 5kHz, depending mainly on the size of the test equipment used.

The frequency is 1MHz.

The calibration method for hydrophones with low-frequency sound pressure fields is given in IEC 60565-2[6]. The calibration method for hydrophones with frequencies above 1 MHz is given in IEC 60565-2[6].

62127-2[7].

This document does not include. calibration of low frequency sound pressure field hydrophones; calibration of digital hydrophones and systems; calibration of ocean self-contained sound recorders;

Calibration of vector sensors, such as particle velocity sensors, acoustic pressure gradient hydrophones; calibration of passive sonar arrays composed of multiple hydrophones; launch Calibration of an active sonar array consisting of a transmitter and a hydrophone.

This document describes the requirements for test facilities, instrumentation, signal processing, and frequency limits for the free-field calibration method.

The achievable uncertainty and reporting rules for calibration data. The informative appendix provides the following guidance.

- Measurement of the directional response of a hydrophone or transmitter;

- Measurement of hydrophone and transmitter electrical impedance;

- Electrical load correction;

- Acoustic far-field criteria in underwater acoustic calibration;

- Pulse techniques in free-field calibration;

- Uncertainty assessment of free-field calibration of hydrophones and transmitters;

- Derivation of the three-transducer spherical wave reciprocity calibration formula;

- Calibration using a traveling wave tube;

- Hydrophone calibration using optical interferometry;

- Calibration using continuous wave signals in a reverberant water tank.

2 Normative references

The contents of the following documents constitute the essential clauses of this document through normative references in this document.

For referenced documents without a date, only the version corresponding to that date applies to this document; for referenced documents without a date, the latest version (including all amendments) applies to this document.

Note. GB/T 2900.86-2009 Electrical terminology - Acoustics and electroacoustics (IEC 60050-801:1994, IDT) IEC 60500:2017 Underwater acoustic hydrophones – Characteristics of hydrophones in the frequency range 1 Hz to 500 kHz