IEC 62127-2:2007

Overview

IEC 62127-2:2007 - "Ultrasonics - Hydrophones - Part 2: Calibration for ultrasonic fields up to 40 MHz" specifies methods for absolute and relative (comparative) calibration of hydrophones used for ultrasonic measurements in water. The standard applies to hydrophones with circular piezoelectric sensor elements (pulsed and continuous wave) and covers devices with or without integral pre-amplifiers. IEC 62127-2 was published together with Parts 1 and 3 and replaces several earlier IEC standards (see Related Standards).

Key topics and technical requirements

• Calibration methods: Defines free-field reciprocity techniques (two‑, three‑transducer and self‑reciprocity), planar scanning (absolute) methods and optical interferometry for calibrations up to 40 MHz, plus comparison calibrations using a standard hydrophone.
• Measurement system requirements: Mechanical positioning accuracy (axial and lateral), temperature measurement and stability, vessel and water properties, hydrophone size limits and recommended calibration intervals.
• Electrical considerations: Signal types, earthing, measurement of hydrophone output voltage, electrical loading by instruments and cables, noise, RF cross‑talk, and handling of integral pre‑amplifiers.
• Procedures & reporting: Stepwise procedural requirements for each calibration technique, recommended data to report, and guidance on measurement corrections.
• Uncertainty and corrections: Informative annexes address uncertainty assessment for free‑field calibration, electrical loading corrections, phase response determination, waveform concepts and the behavior of PVDF polymer sensors in high‑intensity fields.

Practical applications

IEC 62127-2 is used to ensure traceable, repeatable hydrophone sensitivity and phase measurements for ultrasonic fields up to 40 MHz. Typical applications include:

• Calibration laboratories performing hydrophone calibration and measurement traceability.
• Manufacturers of ultrasonic transducers and systems (medical, industrial, NDT) verifying acoustic output.
• Medical device test houses measuring diagnostic and therapeutic ultrasound fields.
• Research institutions characterizing ultrasonic fields, phases and waveforms.
• Quality assurance and regulatory compliance where standardized acoustic metrology is required.

Using this standard helps reduce measurement uncertainty, ensure consistent reporting, and support conformity assessment for ultrasonic equipment.

Related standards

• IEC 62127-1, IEC 62127-3 (published simultaneously) - companion parts of the hydrophone series.
• Replaces: IEC 60866:1987, IEC 61101:1991, IEC 61102:1991, IEC 61220:1993 and IEC 62092:2001.
• Note: Corrigendum of August 2008 is included in this edition.

Keywords: IEC 62127-2, hydrophone calibration, ultrasonic fields up to 40 MHz, reciprocity calibration, planar scanning, optical interferometry, calibration uncertainty.