What is the difference between electromagnetic interference and radio frequency interference?

Answer 1

Electromagnetic interference, EMI, is any undesirable electromagnetic emission or any electrical or electronic disturbance, man-made or natural, which causes an undesirable response, malfunctioning or degradation in the performance of electrical equipment.

Radio frequency interference, RFI, is any undesirable electrical energy with content within the frequency range dedicated to radio frequency transmission. Conducted RFI is most often found in the low frequency range of several kHz to 30MHz. Radiated RFI is most often found in the frequency range from 30MHz to 10GHz.

Answer 2

A simple analogy with ocean water waves: think of EMI as the random small waves that hit the beach all the time and EMP as a tsunami wave.

EMI has many sources: the sun, lightning, electric motors, power lines, the big bang, etc. It interferes with the operation of radio receiving devices, but does not cause damage.

EMP has one main source: nuclear explosions inside the ionosphere (although much weaker EMPs can be generated using special high power electronic RF pulse generators). It damages any equipment (both electronic and electrical) exposed.

Answer 3

"Field" means there is something around a charged object, for example, or around a magnet, which affects nearby charges or magnets. "Electromagnetic radiation" means that any CHANGES in such a field will propagate through space as an ELECTROMAGNETIC WAVE.