# Calibrating the relative intensity of a spectrometer with a blackbody source?

I am trying to compare the relative brightness of $H \beta$ and $H\alpha$ lines using a CCD spectrometer. In order to correct for the different grating efficiency at the two different wavelengths. I took the spectrum of a 100W bulb to use as a blackbody source. I also know the pixel location that correlates to the $H\alpha$ and $H \beta$ line.

I am wondering how to translate the blackbody spectrum to a relative intensity calibration. I thought to try to approximate the peak and use Wien's law to get the temperate of the filament and use that temperature in the Planck's law equation. However, I was unsure if there was a standard method of obtaining a relative intensity calibration for a spectrometer.

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If no answers come to this question after a couple days, you may want to consider posting it on astronomy. – Kyle Kanos Jul 9 '14 at 1:39
I don't know, but I have some warnings. 1.) The spectrum of a 100 W bulb differs somewhat from a blackbody curve due to the effect of the envelope and the variation of emissivity of the filament. Tungsten-halogen are different still. 2.) The peak of the blackbody spectrum for a typical light bulb is in the IR, and likely outside the range of the CCD 3.) the peak you observe in the recorded spectrum will be due to a combination of the spectral curve of the source and that of the detector. That is, it will not be the peak given by Wien's Law. – garyp Jul 9 '14 at 1:50
... BTW, calibrated incandescent sources can be purchased. Watch out, they may have quartz envelopes and emit enough UV to require that you wear special clothing to avoid any skin exposure. – garyp Jul 9 '14 at 1:52
Sorry about the third comment. I don't know why I neglected this: if you can get your hands on an optical pyrometer you can get an idea of the filament temperature. Better to use a clear envelope. – garyp Jul 9 '14 at 1:58