This page will sum-up as much information as possible on the subject of ultraviolet or UV/visible spectrometry. It will concentrate on the task of improving the methods to collect data in the 350 - 400nm and possibly below 350nm wavelengths, cameras and gratings permitting ###CMOS camera sensors### [some data](http://publiclaboratory.org/notes/warren/12-12-2010/can-we-use-back-illuminated-cmos-video-cameras-uv-imaging) shows that rear- or back-illuminated CMOS sensors are sensitive down past 200nm in the ultraviolet. ![CMOS graph](https://publiclab.org/sites/default/files/imagecache/default/Screen%20shot%202010-12-12%20at%207.54.59%20PM.png) ###Non-glass optics### Presumably glass lenses will cut off anything below 350nm, so to take full advantage of this we might consider using a pinhole instead of a glass lens. Luckily webcam lenses just unscrew. Please post here if you try this! > Jack Summers sez: According to these guys: http://dx.doi.org/10.1016/j.aca.2006.09.001, you can detect CO2 at 193 nm... You would, however, need a specialized lamp to do absorbance measurements, and things like plastic and normal glass optics are not going to work at that wavelength. > ToF sez: Pyrex-Lenses should work, but between 200 and 150nm the O2 in the air is very absorbing. Below comparative specta for Borosilicate glass (Pyrex, BK7...) plotted against regular Soda-Lime glass: Borosilicate vs Soda-Lime Glass absorption spectra We see that regular glass lenses and optics would start curring off significantly below 350nm where Borosilicate glasses would start filtering below 335nm ###UV light tests### Recent tests have shown that 360nm and higher is possible, by calibrating a spectrometer and then pointing it at an ultraviolet light. The spectrometer was near-IR capable (had been modified). These tests were based on [this work from Feb 2012](http://publiclaboratory.org/notes/warren/2-14-2012/ultraviolet-spectroscopy-test-350nm) and were done with glass optics still in place.