Kathy, RFI (Radio Frequency Interference) is an old term (circa 1977-1982) which referrred to the interference which could be produced by equipment and be picked up by other equipment (i.e. a PC radiating radio waves which were then picked up by a nearby TV, causing hash or snow on the screen). The US regulations were FCC Part 15 (and still are).
The term RFI was replaced by EMI around 1982 because EMI (Electromagnetic Interference) sounded more descriptive. It meant the same thing. The same regulations applied. EMC (Electromagnetic Compatability) is the latest nomenclature, and does encompass more than EMI. Not only does it mean that the equipment is not to be harmfull to surrounding equipment (i.e. PC is not to interfere with TV pictures), but also the equipment is to perform satisfactorily while in the midst of other equipment which send out harmfull effects. The harmfull effects originally started out as RF radiation from other equipment (3V/M), electrostatic discharges (6-8KV), and transcients on the line and I/O ports (1 to 0.5 KV), but more recently have come to include line voltage swings and dropouts, harmonic distortions, modulating the carrier of the 3V/m signal with an AM signal, etc. The requirements are proliferating. Who is in back of this, you might ask, and the answer is the European Community. The US has no immunity requirements at this time. It will be interesting to read the other responses that you will get. Gabriel Roy Hughes Netwrok Systems MD The opinions expressed above, while probably accurate, do not necessarily reflect those of my Hughes Network Systems. So what. "Psychic hotlines. Shouldn't they be calling you?" ----------------------------------- snip ------------------------------------------------- Hi, I am a safety person who needs to answer a question from one of our sales people on the question of "EMC" verses "RFI". Is there anyone out there who can explanation the differences between "EMC" and "RFI" and how they relate to each other. I would appreciate your comments. Kathy Toy Sun Microsystems, Inc.
