The magnetic fields to which equipment is subjected to every day may influence the reliable operation of equipment and subsystems.

The magnetic field test is intended to demonstrate the immunity of equipment when subjected to power frequency magnetic fields related to the specific location and installation condition of the equipment (e.g. proximity of equipment to the disturbing source). The power frequency magnetic field is generated by power frequency current in conductors or, more seldom, from devices (e.g. leakage of transformers) in the proximity of the equipment.

This standard states that no testing is necessary if the product would inherently be immuned. This test is very simple to perform and it is less costly to perform the test then to spend time to justifying not testing in the final report.