IEC 60565-2:2019 specifies the methods for low frequency pressure calibration of hydrophones at frequencies from 0,01 Hz to several kilohertz depending on calibration method.
IEC 60565-2:2019, together with IEC 60565-1, replaces the second edition of IEC 60565 published in 2006. This edition constitutes a technical revision.
IEC 60565-2:2019 includes the following significant technical changes with respect to the previous edition.
1) IEC 60565 has been divided into two parts:
• Part 1: Procedures for free-field calibration;
• Part 2: Procedures for low frequency pressure calibration (this document).
2) A relative calibration method has been added to Clause 8: Calibration by piezoelectric compensation.
3) A relative calibration method has been added to Clause 11: Calibration by vibrating column.
4) Clause 12: Calibration by static pressure transducer, has been added.
5) Annex A: Equivalent circuit of the excitation system for calibration with a vibrating column, has been deleted.
6) Subclauses 9.6, 9.7 and 9.8 have been moved to form a new Annex A: Advanced acoustic coupler calibration methods.