EMC – electromagnetic compatibility

The term electromagnetic compatibility describes the extent to which a technical device influences other devices via electrical or electromagnetic fields. The European EMC Directive defines the term as follows:

“The ability of a device, installation or system to work satisfactorily in the electromagnetic environment without itself causing electromagnetic interference which would be unacceptable for all devices, installations or systems in this environment.”

If a device exhibits electromagnetic compatibility, it has no effect on other devices or applications. Effects could be influencing the other device or the other application with regard to electrical, electromagnetic, magnetic or sensory fields. This is called galvanic coupling when the currents of two circuits interfere with a common impedance, capacitive coupling when there are interferences in different spatially adjacent electrical circuit parts, which are coupled as a result of stray capacitances, e.g. in the case of parallel conductors on a printed circuit board, and inductive coupling interference caused by the change in the magnetic flux of a magnetic field, e.g. in magnetic resonance applications, and from radiation coupling in the case of electromagnetic interference, e.g. in radio or radio equipment.

Devices with electromagnetic compatibility are therefore subject to certain requirements with regard to structure, functionality and materials of the components. In order to be able to measure these with regard to their compatibility, there are EMC guidelines and standards. It is not only the interference generated by the device that matters, but also the device’s susceptibility to interference from the respective application. In Germany, the VDE or DKE is responsible for creating and editing the standards.

PTM mechatronics has developed a ferrite-free and therefore magnetic-field-free compressed air motor especially for sensitive applications with magnetic fields that require a solution with electromagnetic compatibility. Due to its simple mechanical structure, its trouble-free functionality and the special selection of materials, replacing iron-containing and thus magnetic components with risk-free materials such as plastic or ceramics, it is suitable, for example, for MRI applications, facial locators or TESLA applications: