Xref: utzoo misc.consumers:4784 sci.electronics:2905
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From: larry@kitty.UUCP (Larry Lippman)
Newsgroups: misc.consumers,sci.electronics
Subject: Re: fluorescent lights and my brain
Message-ID: <2505@kitty.UUCP>
Date: 3 May 88 19:21:05 GMT
References: <530@scourge> <1182@ssc.UUCP> <1532@dataio.Data-IO.COM> <2443@ttidca.TTI.COM>
Sender: nobody@sunybcs.UUCP
Organization: Recognition Research Corp., Clarence, NY
Lines: 37
Summary: Phosphors in fluorescent lamps...

In article <2443@ttidca.TTI.COM>, hollombe@ttidca.TTI.COM (The Polymath) writes:
> 
> Question:  Ignoring the physiology for a moment, why don't they use long
> presistence phosphors in fluorescent tubes?  That should smooth over any
> possible flicker effects.

	Persistence is one characteristic used in the selection of phosphors
for fluorescent lamps.  However, from a practical standpoint, there is not
much choice in this area since phosphors must also exhibit the following
characteristics:

1.	Be of inorganic material, stable, and be able to withstand high
	temperatures and other conditions during lamp manufacture and
	subsequent operation.

2.	Have strong optical absorption at 185 and 253 nm with resultant
	fluorescence.

3.	Have minimum absorption at visible light wavelengths.

4.	Have minimum fluorescence in near-IR and near-UV regions.

5.	Maximum fluorescence must occur between 40 and 50 deg C.

6.	Must retain fluorescent characteristics over long period of
	time.

7.	Must be capable of being prepared in fine powder form.

8.	Must have minimum toxicity.

	Finding a "happy medium" for the above ain't easy.  And you want
persistence, too? :-)

<>  Larry Lippman @ Recognition Research Corp., Clarence, New York
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