Black poly blocks RF

Hi,

I am a member of an internet forum with a guy claiming that black poly
(standard black plastic) blocks RF. I am not sure if he is on drugs or is
some kind of super physicist, because he is very confident but IMHO is
talking rubbish.

He is extracts of what he has said (I only cut out parts that don't
contribute to his argument):

"I just wanted to drop off my 2 cents cause this topic happens to be under
my area of expertise.

When manufactures claim something is RF shielded, it means that most of the
electrical components are cover with a high carbon content polymer (aka
black plastic!). It's that simple. However, it's very difficult to shield
all the RF emitting from the power cord connection, so usually no ballast is
perfectly shielded.

There's an easy solution if you are having RF interference problems.
Surround the area/room/cabinet that contains the ballast with a layer or two
of black poly. Remember, black plastic absorbs RF like a sponge, where as
metal reflects it like a mirror. Wet wood absorbs RF like a champ too but
that's not as easy to work with as black poly.
"

"What about there very nature makes plastics non-conductive? High carbon
content plastics do indeed attenuate RF emissions because carbon is
conductive to EM radiation in most pratical spectral bands. So yes, black
poly will attenuate most RF signals!"

"Infinite resistance! Well that sounds like the perfect material to
attenuate a signal with!

But seriously, I have the same black poly as you do. Your ohm meter measures
a material's ability to conduct a DC electrical signal which is completely
different from a material's ability to conduct an electromagnetic wave.

You'll need a spectrum analyzer; UHF antena; function generator; and a
little more insight on the nature of photons to be able to measure a
material's resistance to an electromagnetic wave.

You should really trust me on this one because as it turns out the electrons
in the carbon atom get really excited when they get hit with photons that
are about 100 nanometers to several feet in length. This causes them to jump
to a higher energy state and absorb some of the energy from the wave in
doing so. An RF signal is just a stream of photons that are a couple
centimeters to serveral feet in length. Hence, plastics containg carbon
atoms attenuate RF signals. Isn't that great!
"

"It would take a layer of black poly an inch thick to completely block a
cell phone signal"

Am I woefully misinformed or does he have a point?

Thanks.


.

Relevant Pages

  • Re: Black poly blocks RF
    ... When manufactures claim something is RF shielded, it means that most of the electrical components are cover with a high carbon content polymer. ... High carbon content plastics do indeed attenuate RF emissions because carbon is conductive to EM radiation in most pratical spectral bands. ... You should really trust me on this one because as it turns out the electrons in the carbon atom get really excited when they get hit with photons that are about 100 nanometers to several feet in length. ... plastics containg carbon atoms attenuate RF signals. ...
    (sci.electronics)
  • Re: Carbon sequestration
    ... World production of oil has peaked, or is just about to, but in general the amount of oil which will be produced in future is fixed, and in practice I don't think there is anything we can do to change it. ... This isn't really storing up a problem for the future - in a few hundred years the carbon crunch will be solved, ... I'd also like to see all biodegradeable and oxo-degradeable plastics banned. ... released - and if it is put into landfill in plastic bags, and if the landfill company doesn't break up the bags, it stays there much longer. ...
    (uk.environment.conservation)
  • Re: wideband inductors
    ... prevent inductors from 'seeing each other'. ... Except for very tiny holes to pass signals each stage ... Our 'new' stereo quits everytime a pilot announces entering ... With plastics it is the other way around, ...
    (sci.electronics.design)
  • Re: Microwave oven catches fire. Repairable?
    ... whole oven or using it without any window (no window could become a ... Amateur radio enthusiasts have been putting plastics (dielectrics) ... into microwave ovens for years to see if they absorb microwave energy ... turns things to carbon, which you dont want in a nuke. ...
    (sci.electronics.repair)
  • Re: realistic aliens and the necessities of storytelling
    ... we need a single world authority issuing carbon ... If you actually had a carbon tax, it would look quite unlike current ... absorbs carbon would get a subsidy, ... perspex would be ok too, but not vinyl, or other chlorinated plastics. ...
    (rec.arts.sf.composition)