Subject:  (Philips) EMF's and Fluoroscent Lights (fwd)
Date:     Mon, 23 Nov 1998 033505 -0600 (CST)
From:     "Roy L. Beavers" <rbeavers@llion.org>
To:       emfguru <rbeavers@llion.org>
--------------------------------------------------


---------- Forwarded message ----------
Date: Sun, 22 Nov 1998 18:48:09
From: Alasdair Philips 
To: "Roy L. Beavers" 
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 
light 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
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Alasdair Philips    (aphilips@gn.apc.org)
Director, UK Powerwatch,
EMC Engineer and EMF-bioeffects researcher
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Alasdair Philips    (aphilips@gn.apc.org)
Director, UK Powerwatch,
EMC Engineer and EMF-bioeffects researcher
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~



Archive provided courtesy of WaveGuide, http://www.wave-guide.org
Reprinted with permission of Roy Beavers, http://www.feb.se/EMF-L/EMF-L.html