On page 26 (PDF page 30) the FCC's Human Exposure to RF Guidelines document,

http://www.fcc.gov/Bureaus/Engineeri...t65/oet65c.pdf

There is a nice chart for MPE limits. However, there is no information given
for frequencies below 300kHz. Does anyone know what the MPE limits would
be for both electric and magnetic field strength at 80kHz?

Thanks,
-Chris

--
/ Christopher Cole \ \
Cole Design and Development \\ email: \\
\\ Computer Networking & Embedded Electronics \\ web: http://coledd.com
\ \ /

On Wed, 5 Jul 2006, Christopher Cole wrote:

On page 26 (PDF page 30) the FCC's Human Exposure to RF Guidelines document,

http://www.fcc.gov/Bureaus/Engineeri...t65/oet65c.pdf

There is a nice chart for MPE limits. However, there is no information given
for frequencies below 300kHz. Does anyone know what the MPE limits would
be for both electric and magnetic field strength at 80kHz?

I'm going to make a guess on this. At pretty low f, absorbtion starts to
go down. I know they communicate with submarines with RF carriers around
12-14 kc because ocean water is almost transparent. Only when absorption
of RF gets high then there are "bioeffects" (mostly thermal, but there is
controversy about non-thermal effects). Others here might be able to be
more specific for that range 14 khz to 300 khz.

Thanks,
-Chris

--
/ Christopher Cole \ \
Cole Design and Development \\ email: \\
\\ Computer Networking & Embedded Electronics \\ web: http://coledd.com
\ \ /

Christopher Cole wrote:

There is a nice chart for MPE limits. However, there is no information given
for frequencies below 300kHz. Does anyone know what the MPE limits would
be for both electric and magnetic field strength at 80kHz?

Thanks,
\ /

Andy comments:
Using the 1992 ARRL handbook regarding the proposed ANSI standard,
Figure 4, page 36-4, I get the following at 80 khz..

Efield : 600 V/m or 100mw/ sq cm ( these are the same levels)

Hfield: 1000 watt/ sq cm ( this is a power density form of H
field)
This is 163 amps/meter

These are for both controlled and uncontrolled environments, and
are DIFFERENT levels.. In other words, the allowable safe H field
is a LOT more powerful than the safe E field .

These are really damn big numbers and I don't think you should worry
much about them unless you play golf in the rain.......... :)))))


Andy in Eureka, Texas W4OAH\



( The chart is small, and my glasses are thick, so I apologize for
any lack of precision.... )