Subject: (Maxey) polarity (fwd)
Date: Mon, 23 Nov 1998 145235 -0600 (CST)
From: "Roy L. Beavers" <rbeavers@llion.org>
To: emfguru <rbeavers@llion.org>
--------------------------------------------------
---------- Forwarded message ----------
Date: Mon, 23 Nov 1998 10:24:34 -0800
From: Edward S Maxey
To: rbeavers@llion.org
Cc: Sheila
Subject: polarity
Hi Roy,
The EMF problem is large enough for every one to put in his
own two cents worth.
Alasdair's insightful remarks are right on the mark. Probably
electricians in the UK are a bit more disciplined than here in
the USA so they do not have one problem with fluorescent
installations occasionally seen here.
Long fluorescent tubes are frequently seen under ceilings in
supermarkets etc. Sometimes two (or more) are placed
side by side parallel to each other. If they are wired so that
their polarities are the same the 50-60 Hz EMFs from the
tubes become additive. If their polarities are reversed the
EMFs tend to cancel out.
Cordially,
Ed
* * * * * * * * * * * * * * * * * *
>Cc: Sheila
>Subject: EMF's and Fluoroscent Lights (fwd)
>
>Dear all
>I've been trying to resist responding so much lately but hear comes
>some more of AllyPally's gems......
>
>Fluorescent lights do usually give off high(ish) EMFs.
>
>(i)If they are 50 or 60 Hz there is usually a magnetic ballast coil
>which can give off high magnetic fields up to a metre or more away.
>
>(ii)If they are high-frequency high-efficiency low-flicker types they
>can give off very high levels of low frequency radio waves. I have
found
>early ones of these types emitting wide band RF noise from 30kHz -
150kHz
>at levels of 80 volts/metre at 1 metre distance and 20 volts/metre at
>about 2 metres distant. I have done spectrum analyser tests on these
>llight fittings.
>
>This often gives people headaches and flu like symptoms. I did one
>building where they had hundreds of these and they changed the lights
>on one floor to test my theory and all the staff felt and worked
>better and had much less sick leave on that floor so the are
>changing the lighting on all six floors of the building now. These
l>ight fittings dated from about 15 years ago.
>
>Most modern HF lights use a 32 kHz watch "clock" crystal oscillator and
so
>only give out 32, 64 and 96 kHz at low levels in order to comply with
the
>tougher modern EMC (interference) regulations. Some of these modern
lights
>are also designed to have low E-fields (1 or 2 V/m at 1 metre distant).
>
>NB Most "gauss-meters" and cheap E-field meters will not pick up VLF
fields
>(c. 2000 Hz - 400 kHz) and so will not detect HF light problems.
>Holoday do a suitable meter (at a price! I have one and it is a useful
>occasional tool. It is also needed to check VDUs for MPRII compliance).
>
>(iii) Most ordinary 50/60 Hz fittings give off highish 50/60 Hz electric
>fields because they use these to keep the tube lit up. It is possible
to
>partially screen for these but fitting an earthed metal grid as part of
>the light diffuser and some makers design conductivity into the
diffuser.
>
>(iv) the flicker from 50/60 Hz units can adversely affect many people.
>
>(v) when fittings "age" and the ends become darker than usual these ends
>give off significant amounts of soft x-rays.
>
>(vi) Having said all that 'damning stuff', in locations where daylight
is
>not possible then 'full-spectrum' 'daylight' tubes which include the
>correct amounts of near UV (UVA and some UVB) are necessary if people
>are to keep fit at well.
>They just need to be good, modern, HF high-efficiency light fittings
>which have been tested for low EMF emissions.
>
>I do not approve of them in bedrooms or resting areas. In my opinion
>the best artificial light in these areas is from 12 or 24 volt direct
>current lamps which do not give off ac EMFs nor do they flicker at
>50 or 60 cycles per second at the people. Even though a normal mains
>incandescent bulb does not appear to flicker to our eyes, it is actually
>doing that. If you take a photodiode and connect it into a sensitive
>audio High-Fi amplifier and take it into a room with ordinary mains
>bulbs you will hear a loud hum from the loudspeakers. If you shield the
>photodiode from the light the hum will go away (if the input lead to
>the amplifier is screened properly to avoid electrical hum pickup).
>Even though we can't see it this light (amplitude) vibration is hitting
>our bodies. It may, or may not, be adversely affecting our bio-systems
>but our bio-systems certainly hear/feel it.
>
>...EMF-L: the only place to hear all my wisdom for free!.... Thanks,
Roy!!
>
>In peace
>
>Alasdair
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