There is a very small amount of mercury in fluorescent lamps to
encourage ionization; Much more in mercury vapor lamps.

Fred Townsend


From: [email protected] [mailto:[email protected]] 
Sent: Friday, March 27, 2009 2:18 PM
To: [email protected]
Subject: Re: [PSES] Hg in Display Units - MA Legislation

I was under the impression that vacuum fluorescent displays are
high-vacuum
triodes, not gas/mercury triodes, where the anode is coated with a
phosphor
that glows when struck by electrons (no mercury involved, similar to the
"magic eye" tubes that were popular in radios during the 1930s for
tuning
indicators, and more akin to CRTs than fluorescent lamps).

Fluorescent lamps are relatively low vacuum diodes (that conduct both
directions), where the mercury is excited by electrons, emits
ultraviolet
as it returns to ground state, and then the phosphors convert the
ultraviolet to visible light.

Donald Borowski
Schweitzer Engineering Labs
Pullman, WA, USA

[email protected] wrote on 03/27/2009 12:00:02 PM:

> Hello Listees,
>
>         I have just learned about recent legislation in
> Massachusetts that requires manufacturers of products containing Hg
> to register with the state and establish recycling programs. My
> company markets deli scales, some of which use a vacuum fluorescent
> display lit by very small fluorescent lamps. I understand that
> computer monitors use the same type of lamps.
>         I find it hard to believe that there wouldn't be an
> exemption for users of such small amounts of Hg. I am familiar with
> the Northeast states IMERC regulations and these same units already
> comply with their usage reporting, marking and instruction manual
> requirements.
>         I'd appreciate if any of the other manufacturers within this
> group, whose products also use these small fluorescent lamps, would
> comment concerning how they're complying with the new regulations.
>         Thanks in advance.
>
> Good day,
>
> Richard I. Pittenger
> Agency Approval Engineer
> Food Retail Systems
> Hobart

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