IEC 60404-10:2016

Overview

IEC 60404-10:2016 - Magnetic materials - Part 10 - specifies methods for measuring a.c. magnetic properties of grain‑oriented and non‑oriented electrical steel strip and sheet in the medium frequency range (400 Hz to 10 000 Hz). The standard defines the general principles, apparatus and measurement procedures (notably using an Epstein frame) and incorporates modern evaluation techniques. This is Edition 2.0 (2016) and includes the March 2018 corrigendum.

Key topics and technical requirements

• Scope and frequency range: Applies to electrical steel strip and sheet for a.c. magnetic testing at 400 Hz–10 000 Hz.
• Measurement method: Defines the 25 cm Epstein frame method as the principal test arrangement for comparative and standardized measurements of strip/sheet.
• Quantities measured:
  • Specific total loss (core loss) at medium frequencies
  • Peak magnetic polarization (J)
  • r.m.s. value and peak value of magnetic field strength (H)
  • Specific apparent power (S)
• Modern measurement adoption:
  • Formal introduction of the digital sampling method for data acquisition and evaluation (Annex B), reflecting contemporary instrumentation and numerical processing.
  • Guidance on calibration aspects and requirements for digital sampling systems.
• Air flux compensation:
  • Revised treatment of air flux compensation to address issues that arise at higher test frequencies.
  • Discussion of capacitive coupling in mutual inductor windings and an alternative numerical air flux compensation technique.
• Apparatus and instruments:
  • Epstein frame configuration and jointing details
  • Voltage measurement options (average and RMS voltmeters, peak voltmeters)
  • Current and power measurement circuits (wattmeter methods, mutual inductors)
  • Reference components such as resistors and mutual inductors with capacitive coupling considerations
• Accuracy and reproducibility: The standard explains factors affecting final accuracy and provides reproducibility guidance where agreed by the technical committee.

Practical applications and users

Who uses IEC 60404-10:

• Magnetics and electrical steel manufacturers for product characterization and quality control
• Test laboratories and certification bodies performing standardized core‑loss and magnetic property testing
• Design engineers in power electronics, transformers, motors and inductors who need material data at medium frequencies
• R&D teams developing new electrical steels and magnetic alloys

Practical value:

• Ensures comparable, repeatable measurements across suppliers and labs
• Supports selection of electrical steel for medium‑frequency applications (e.g., high switching‑frequency transformers, EMI components)
• Enables modernization of test setups by adopting digital sampling and numerical compensation techniques

Related standards

• Other parts of the IEC 60404 series (Magnetic materials) - consult the IEC catalogue for related measurement methods and terminology.
• Check for the latest edition, corrigenda and national adoptions to ensure compliance with current requirements.