ISM International Standard
wrote in message
ups.com...
I'm familiar with the purpose of the ISM band. My question is why is it
important that the ISM band be the same around the world? I've looked
at the FCC site and the ITU and I didn't find an answer.
Kensei
Because the ISM equipment is shipped around the world and the interference
from such equipment can cause interference which can also propagate around
the world.
Consider 27MHz, this is an ISM band and diathermy machines make a hell of a
racket. When propagation is good, only a few watts is required for
international communications. These machines leak RF and it can cause RF
interference around the world, that is, unless the rest of the world is also
using the same frequency.
It reduces the cost of manufacture if all the medical machines use the same
frequency bands instead of having to redesign them to suit each country.
Same applies to industrial and scientific applications. It's called band
planning.
Brad.
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