Relative intensity changing with temperature?

[AdrianH]

I am trying to determine the temperature in a discharge lamp. I have the spectrum of that lamp and Nist Atomic Spectra Database. I don't have the pressure in the lamp (can I determine that too? How?). The spectrum that I have has a low resolution (of about 0.3 nm). Can this be done?
1) One method that I know is to compare 2 distinct lines that represent the transitions from one energy level to two fairly different energy levels or transitions from two different levels to a single level (am I wrong?).
2) Checking the broadening and the self-absorbtion of a line (assuming that the pressure is sufficient), but I don't know much about this. Can someone explain this technique or point me to the literature (would the resolution be enough for this?)

(sorry for my english, I'm romanian)

 

[Andy Resnick]

The problem is that discharge lamps don't have a blackbody spectrum (or even a close approximation), so determining a thermodynamic temperature is problematic.

There are numerous ways to assign a temperature based on the relationship between your lamp output and that of a blackbody radiator (effective temperature, etc.)

The broading of the line could probably give you a pressure measurement- look up "homogeneous line broadening", but I would be surprised if the number was significantly different than the manufacturer spec.