Naked Science Forum

General Science => General Science => Topic started by: lennie on 12/04/2008 23:38:31

Title: Could a fluorescent tube be made of clear glass to emit more light?
Post by: lennie on 12/04/2008 23:38:31
Can one have a clear tube and therefor more light?
Title: Re: Could a fluorescent tube be made of clear glass to emit more light?
Post by: graham.d on 13/04/2008 00:06:20
No. The definition of a fluorescent tube is that it relies on fluorescence. The discharge in the tube produces UV light which then is absorbed by the fluorescent coating and re-emitted in the visible spectrum. You can have clear discharge emissions, like a sodium light for example, but then there is no fluorescence involved.
Title: Could a fluorescent tube be made of clear glass to emit more light?
Post by: techmind on 18/04/2008 20:45:58
No. The definition of a fluorescent tube is that it relies on fluorescence. The discharge in the tube produces UV light which then is absorbed by the fluorescent coating and re-emitted in the visible spectrum. You can have clear discharge emissions, like a sodium light for example, but then there is no fluorescence involved.

I've got a "clear" tube - it gives off a sky-blue light... and lots of ultraviolet. This is the natural colour of the (mercury) discharge. If I had more time I'd do you a nice photograph!

As Graham says, they put the white phosphor on the tube to convert that ultraviolet to visible. The visible light you see from a fluorescent tube is generated in the white coating on the inside of the glass - and is much brighter than the bluey/UV "inside" light would be.