IEC 60404-3:2022

Overview

IEC 60404-3:2022 - Magnetic materials - Part 3 - specifies the methods for measuring the AC magnetic properties of electrical steel strip and sheet using a single sheet tester (SST). It applies to both grain‑oriented (GO) and non‑oriented (NO) electrical steels at power frequencies and defines general principles, test apparatus, measurement procedures and reporting requirements for properties such as specific total loss, specific apparent power, magnetic polarization (J), and magnetic field strength (H).

This 2022 edition revises annexes and measurement details (notably adding a method to determine yoke lamination resistance, canceling the previous Epstein‑based calibration annex, and introducing numerical air flux compensation in Annex D).

Key topics and technical requirements

• Single Sheet Tester (SST) principle: Defines the SST measurement concept, coil arrangements and how specimens are mounted between yokes for AC testing.
• Test apparatus requirements: Specifications and manufacturing requirements for yokes, windings and power supply arrangements to ensure reproducible SST measurements.
• Measurement procedures:
  • Determination of specific total loss (P) and associated measurement circuits and instrumentation (voltage, frequency, power measurement).
  • Determination of magnetic field strength (H), peak magnetic polarization (J), excitation current (r.m.s. and peak) and specific apparent power (S).
  • Preparation, source adjustment and reproducibility checks described to ensure comparable results.
• Air flux compensation: Methods for compensating stray/air flux in the SST; Annex D includes digital sampling methods and a new clause on numerical air flux compensation.
• Yoke characteristics: Annex A updated to include determination of the yokes’ lamination resistance, important for accurate loss separation.
• Calibration and reference relations: Annexes provide informative material on SST performance checks and the Epstein-to-SST relationship (Annex C) for grain‑oriented steels; the Epstein‑based calibration annex from the consolidated 2010 version was cancelled and replaced with revised informative guidance.

Applications and who uses it

IEC 60404-3:2022 is intended for:

• Manufacturers of electrical steel (quality control, production acceptance)
• Independent testing and calibration laboratories
• R&D teams developing magnetic materials and processing routes
• Designers and specifiers of transformers, inductors and electric machines who require standardized loss and magnetic‑property data
• Standards bodies and certification organizations verifying measurement conformity

Practical outcomes include standardized, comparable measurements of AC losses and magnetic characteristics used for material selection, process optimization and performance prediction in power‑frequency magnetic devices.

Related standards and keywords

• Related IEC 60404 series parts (magnetic materials)
• Keywords: IEC 60404-3:2022, single sheet tester, electrical steel, magnetic properties, specific total loss, specific apparent power, grain‑oriented, non‑oriented, yoke lamination resistance, air flux compensation, Epstein conversion, numerical air flux compensation.