Emission lines of flourescent bulbs

[Chi Meson]

Hey

does anyone know of a site where I can get the wavelengths of the strong emission lines of standard compact flourescent bulbs? It's very similar to mercury emission lines, but not the same exactly.

 

[Astronuc]

I went looking on-line and most sites do not go into such detail. There may be ISO or ASTM standards on the color or chromaticity of these lights, but I have not found a specific table of frequencies.

If you have access to a optical spectrometer, you might consider buying a compact fluroescent lamp and actually measuring the emission lines.

 

[Chi Meson]

The CF bulbs are plentiful. It's the spectrometer that's harder to get!

 

[Astronuc]

I found this document which contains descriptions of various kinds of light bulbs.

http://www.powerhousetv.com/stellent2/groups/public/documents/pub/phtv_000476.pdf

The long fluorscent bulbs contain mercury and 'inert gases', e.g. Ne, Ar, and the phosphor coating on the inside of the glass. So the emission spectrum will be that of the mercury, inert gases, and whatever phosphor which diffuses visible light and interacts with the ultraviolet light from mercury to produce its own visible light. The relative intensity of the lines will depend on the energy of the electrons in the current, the temperature and the composition (proportions) of Hg and inert gases.

Unfortunately, I did not find an emission spectrum of compact fluorescent bulbs, and I suspect such a spectrum will be unique to the particular model. I also imagine that the precise spectrum is considered proprietary, because the best color rendering would be considered an economic (competitve) advantage.

Perhaps you should email the manufacturers and ask them directly for the information, which unfortunately may take some time.

There is also another document which discusses color lighting standards for photography, but I don't know how useful it would be.

http://www.colour.org/tc8-04/Standards/FDIS3664.pdf

or contact someone at:

COMMISSION INTERNATIONALE DE L'ECLAIRAGE
INTERNATIONAL COMMISSION ON ILLUMINATION
INTERNATIONALE BELEUCHTUNGSKOMMISSION
http://www.colour.org

Meanwhile, since you have aroused my scientific curiosity, I'll keep looking.

 

[Chi Meson]

Thanks for your help. After an "advanced" google search, I have found a site that does answer my question:
http://www.assumption.edu/users/bniece/CHE131/LineSpectra/Index.html
It has spec data on a number of gasses as well as CF and filament bulbs.

Your point about proprietary spectra is a good one, and I will keep it in mind.

 

[Astronuc]

That is cool. You can see how the CFB spectrum attempts to replicate the incandescent spectrum, but the CFB more or less uses a discrete as opposed to continuous spectrum.

It would be interesting to compare spectrum of different bulbs and compare them with a mercury lamp.

One of the experiments in an experimental physics class was to use a spectrometer to observe the emission spectra of different elements including the mercury spectrum. We also had to determine a mystery composition.