[alt-photo] Re: Metal halide lamps in plate burners and ozone???

[BOB KISS]

DEAR LORIS,
	Please note that there is a fan built into the top of the light
housing holding the lamp and reflector and I have another exhaust fan built
into my darkroom ceiling which pulls darkroom air out the top and blows it
outside my roof.  
	I haven't paid attention to the fan in the light housing so I
haven't noticed if it changed speed during exposure.  I believe its purpose
is to keep the metal halide bulb (NP80 in our case) from overheating by
circulating air around it.
	Ozone is hard to describe...it has a sort of sweet but bitter smell.
You can sometimes smell it after lightning strikes during a storm.  Also, if
you have an electronic flash of any reasonable power, you can smell ozone
rising above it right after a flash.  
Some people think it has positive health effects but the research shows that
repeated exposure to higher concentrations can cause health problems.    
		CHEERS!
			BOB

-----Original Message-----
From: alt-photo-process-list-bounces at lists.altphotolist.org
[mailto:alt-photo-process-list-bounces at lists.altphotolist.org] On Behalf Of
Loris Medici
Sent: Friday, April 16, 2010 9:38 AM
To: 'The alternative photographic processes mailing list'
Subject: [alt-photo] Re: Metal halide lamps in plate burners and ozone???

Dear Bob,

I noticed that the plateburner slows down the speed of the exhaust fan on
the top during exposure -> do you think that's because of ozone generation?
I don't know how ozone smells and I don't notice any additional smell in the
room during or right after exposure. Go figure! Can you describe the smell
of ozone? (If that's possible...)

Thanks,
Loris.


-----Original Message-----
From: alt-photo-process-list-bounces at lists.altphotolist.org On Behalf Of BOB
KISS
Sent: Friday, April 16, 2010 4:27 PM
To: 'The alternative photographic processes mailing list'
Subject: [alt-photo] Re: Metal halide lamps in plate burners and ozone???

DEAR LORIS,
	I have my plate burner (also NP80 bulb) right under my exhaust fan
in the ceiling so I don't have an ozone problem but when I had it previously
located in a smaller darkroom, I could smell ozone during and immediately
after exposure.  However, I used to open the darkroom door and put on a fan
during exposure because ambient room light won't cause any problems to the
sensitized material under your neg in the vacuum frame.
		CHEERS!
			BOB

-----Original Message-----
From: alt-photo-process-list-bounces at lists.altphotolist.org On Behalf Of
Loris Medici
Sent: Friday, April 16, 2010 7:21 AM
To: 'The alternative photographic processes mailing list'
Subject: [alt-photo] Metal halide lamps in plateburners and ozone???

Hi all. Now that I have/use a NuArc plateburner, I was wondering if the
lightsources of this and similar devices generate ozone? I have the
plateburner in a not too big room (14m2 / 150 sq. ft.), should I be
concerned with the amnt. of ozone that will be - presumably - generated?

TIA,
Loris.

P.S. The plateburner I have uses a NuArc NP80 lightsource. See its spectral
power distribution chart here:
http://www.tcsuvlamps.com/products/222_files/diazo_graph.jpg

_______________________________________________
Alt-photo-process-list | http://altphotolist.org/listinfo

__________ Information from ESET NOD32 Antivirus, version of virus signature
database 5033 (20100416) __________

The message was checked by ESET NOD32 Antivirus.

http://www.eset.com