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.