SDAA522 September   2026 ISO6020 , ISOM8110 , ISOM8110-Q1 , ISOM8113-Q1 , ISOM8610 , ISOM8710 , ISOW6441

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1 Introduction
    1. 1.1 Why Magnetic Field Immunity Matters for Isolators
  5. 2 Magnetic Field Units at a Glance
  6. 3 IEC 61000-4-8 — Power Frequency Magnetic Field Immunity
    1. 3.1 What IEC 61000-4-8 Test Simulates
    2. 3.2 Test Levels for IEC 61000-4-8 Continuous Power Frequency Fields
    3. 3.3 Environment Classes — How a Level is Chosen
    4. 3.4 Field Strengths Observed in Actual Installations
  7. 4 IEC 61000-4-9 — Pulse Magnetic Field Immunity
    1. 4.1 What IEC 61000-4-9 Test Simulates
    2. 4.2 Impulse Current Waveform for Pulse Magnetic Field
    3. 4.3 Test Levels for IEC 61000-4-9 Pulse Magnetic Fields
  8. 5 Summary of Class 5 Testing— What We Are Targeting
  9. 6 What "PASS" Means — Performance Criteria
  10. 7 Test Setup Details
  11. 8 Test Results and Summary
    1. 8.1 Test Conditions for Both Standards:
  12. 9 System Design Considerations for End Equipment Performance
  13. 10Summary
  14. 11References

2 Magnetic Field Units at a Glance

The test standards specify test severity in A/m (magnetic field strength, H), while the commonly known physics equations typically work in Wb/m2or Tesla (magnetic flux density, B). In air, the equations are directly proportional per Equation 1 and Equation 2:

Equation 1. B = μ 0 ×   H
Equation 2. μ 0 = 4 π × 10 - 7 W b / A ×   m
Quantity Conversion
1Wb/m2 = 1T (Tesla)
1A/m ≅ 1.26µT (1.26 × 10-6Wb/m2)
80A/m ≅ 1G
Earth's magnetic field ≅ 0.5G ≅ 40A/m
100A/m (IEC 61000-4-8 Level 5, continuous) ≅ 126µT
1000A/m (IEC 61000-4-9 Level 5, pulse) ≅ 1.26mT