IEC61000-4-8 Power frequency Magnetic field Immunity

電源頻率磁場抗擾性測試

Power Frequency Magnetic Field Immunity測試系統（又稱LF Magnetic Field Immunity Test）是一種用於評估電子設備對低頻磁場抗干擾能力的測試方法。

在進行Power Frequency Magnetic Field Immunity測試時，測試人員會使用具有可調整磁場幅度的磁場發生器產生一個低頻磁場信號，並將這個信號傳遞到待測設備上。待測設備會在低頻磁場信號下進行操作，而測試人員會監測設備是否能夠正常運行。

在 Power Frequency Magnetic Field Immunity 測試過程中，測試人員會使用不同的測試參數，例如磁場信號的頻率、幅度等。這些參數通常是由相關的EMC標準和規定所指定的。

通過 Power Frequency Magnetic Field Immunity 測試，可以確定設備能夠承受低頻磁場信號的強度和頻率範圍，以及設備在受到低頻磁場信號時是否能夠正常運行。這些測試可以幫助設計人員和製造商確保其產品符合相關的EMC標準和規定。

總之，Power Frequency Magnetic Field Immunity 測試系統是一種用於評估電子設備對低頻磁場抗干擾能力的測試方法，通過模擬低頻磁場信號來確定設備能夠承受低頻磁場信號的強度和頻率範圍，以及設備在受到低頻磁場信號時是否能夠正常運行，以確保設備符合相關的EMC標準和規定。

Power Frequency Magnetic Field Background

Electronic products are often subjected to magnetic fields at AC mains frequencies. These fields are frequently produced in the vicinity of power transformers and can cause problems with video displays, Hall effect sensors, and other electronic products having a sensitivity to magnetic fields.

Electronic Products are tested for immunity to power frequency magnetic fields to insure their continued reliable operation when placed in service. The European Union’s EMC Directive currently mandates power frequency magnetic field testing for certain categories of equipment as a condition for obtaining the CE Mark before shipping products to member states of the European Union.

Applicable Standards

Generic Immunity, Product and Product Family Standards require that Power Frequency Magnetic Field tests be performed in accordance with Basic EMC Standards: IEC 61000-4-8 and EN 61000-4-8. Thermo KeyTek’s Application Note, “EMC Standards Overview,” provides an overview of European Standards for electromagnetic compatibility, describes how the Standards relate to one another, and list sources for procuring copyrighted documents.

Basic EMC Standard

The Basic EMC Standard for Power Frequency Magnetic Field defines methods of generating consistently reproducible magnetic fields for test purposes. Although higher magnetic field levels are described, compliance to the Generic Immunity Standard for residential and commercial products is 1A/m or 3A/m. Currently applicable only to apparatus containing devices susceptible to magnetic fields, testing of other products may be required to make that determination. While the Basic EMC Standard specifies how to perform Power Frequency Magnetic Field testing, the Generic, Product and Product Family Standards specify the test levels and pass/fail performance criteria.

Test Levels

Power Frequency Magnetic Field testing is required for products that could be affected by magnetic fields, including CRTs and Hall Effect Sensors and is strongly recommended for all products.