IEC 60565-2:2019

Overview

IEC 60565-2:2019 is an international standard published by the International Electrotechnical Commission (IEC) that focuses on the calibration of hydrophones used in underwater acoustics. Specifically, this Part 2 document defines procedures for low frequency pressure calibration of hydrophones within the frequency range of 0.01 Hz to several kilohertz. It complements IEC 60565-1, which covers free-field calibration, together forming a comprehensive technical revision over the 2006 edition.

This standard is essential for ensuring accurate, reliable measurement of underwater acoustic pressures at low frequencies-a critical requirement for scientific, industrial, and defense applications where precise underwater sound measurements are necessary.

Key Topics

• Scope and Frequency Range
  Calibration methods described apply to low-frequency pressure measurements from 0.01 Hz up to several kHz, depending on the selected calibration technique.

• Calibration Methods
  IEC 60565-2:2019 introduces multiple low-frequency calibration procedures:

  • Hydrostatic excitation calibration
  • Piezoelectric compensation method (including a newly added relative calibration procedure)
  • Acoustic coupler reciprocity calibration
  • Pistonphone calibration
  • Vibrating column calibration (including a new relative calibration method)
  • Static pressure transducer calibration (newly added in this edition)

• Technical Updates
  The standard was revised to split the original document into two parts and add new methods such as calibration by static pressure transducer and relative calibration methods for piezoelectric compensation and vibrating columns, enhancing accuracy and flexibility.

• Measurement and Reporting Protocols
  Detailed guidelines include electrical measurement setups, correction factors, temperature and pressure considerations, and data reporting to ensure precision and reproducibility.

• Uncertainty Assessment
  Annex B helps users evaluate measurement uncertainty, a crucial aspect for confidence in hydrophone calibration results.

Applications

IEC 60565-2:2019 is applicable across a wide range of practical underwater acoustics tasks requiring highly accurate hydrophone calibration at low frequencies:

• Oceanographic Research
  Calibration ensures precise measurement of underwater acoustic signals for marine biology, seismology, and environmental monitoring.

• Naval and Defense Systems
  Accurate hydrophone calibration supports sonar system performance and underwater surveillance.

• Offshore Industry
  Calibration of hydrophones used in underwater noise monitoring, subsea infrastructure inspection, and environmental impact assessments.

• Underwater Communication Systems
  Optimizing transducer sensitivity for low-frequency acoustic signals used in communication and data transmission underwater.

• Manufacturing and Quality Control
  Testing hydrophone performance during production with certified low-frequency calibration methods.

Related Standards

• IEC 60565-1 – Covers procedures for free-field calibration of hydrophones complementing low frequency methods in Part 2.

• Other Underwater Acoustics Standards
  Standards related to sonar performance, underwater noise measurement, and acoustic sensor specifications may be used in conjunction with IEC 60565-2 to ensure comprehensive system calibration and testing.

• International Electrotechnical Vocabulary (IEV)
  Provides standardized terminology used throughout IEC 60565-2 ensuring consistent communication and understanding within the industry.

Summary

IEC 60565-2:2019 provides a detailed, rigorously defined framework for calibrating hydrophones at low frequencies, critical for underwater acoustics measurement accuracy. Its inclusion of multiple calibration methods, updated technical content, and uncertainty evaluation makes it a vital resource for hydrophone manufacturers, researchers, and professionals working in marine and underwater acoustic fields. Adhering to this standard ensures dependable hydrophone sensitivity measurements and supports high-quality underwater acoustic data acquisition.