Re: NEON- Re: color checker??

To: neon-l@lists.io.com
Subject: Re: NEON- Re: color checker??
From: Dilling <dilling@erols.com>
Date: Tue, 29 Oct 1996 12:34:50 -0500 (EST)
Reply-To: neon-l@lists.io.com
Sender: owner-neon-l@io.com

MARCUS,

You have a uv laser? 
neat!

matt

At 14:10 96-10-29 +0100, you wrote:
>Dear Matt,
>Soda or pyrex will be transparent for 350nm UV radiation, but will
>behave like black cloth for 254nm. 
>So you can never excite fluorescent powders throgh any glass except
>pure quartz. All powders are primary excited by 254nm, only some mixed
>powders may have additional phosphorescent compunds which are excited by 
>the 350nm range. 
>
>When I'm unsure in a broken unit's color, I light into the tube with a 244nm
>UV laser. So I can see the pure phosphor, but not the tube's color after
>been pumped. To get the right color, you have to add the grren and blue 
>components of the mercury discharge. No color checker can afford this, 
>some parts of the phosphors are excited by the free electrons present in the 
>tube. Color checkers can only be a rough estimation. 
>
>Marcus
>
>
> 
>>  For one thing, it seems that
>> >these Mineral Lites are of short wavelength and won't pass easily
through the
>> >wall of the neon tubing. 
>> >Jeff Golin
>> >
>> >
>> Jeff,
>> I don't know if you work in all soda, but the uv light will amost always be
>> blocked by leaded glass. I Have never seen a color checker that will light
>> up a tube other that on the end. 
>> The story is different of course if you are working in say, soda or pyrex.
>> 
>> matt
>> 
>> 
>
>
>