A CD Spectrometer (2006)
I recently got a spectrometer with a fibre input from fleabay, which I've been enjoying playing with.<p>I got a tiny ruby stone and shone a tungsten halogen light behind it -
<a href="https://www.anfractuosity.com/files/ruby.png" rel="nofollow noreferrer">https://www.anfractuosity.com/files/ruby.png</a> I could see a dip around 694nm like someone else's spectrum - <a href="https://en.wikipedia.org/wiki/Ruby_laser#/media/File:Ruby_transmittance.svg" rel="nofollow noreferrer">https://en.wikipedia.org/wiki/Ruby_laser#/media/File:Ruby_tr...</a>.  This is the same wavelength that ruby lasers emit light apparently.<p>I'm planning on using it to try to measure ABV of beer/spirits.  I noticed some of the cuvette holders with fibre inputs seem to be crazy expensive though, so probably need to DIY that!<p>A while ago I got a little spectroscope that looked a bit like - <a href="https://shop.wf-education.com/science/op66595.html" rel="nofollow noreferrer">https://shop.wf-education.com/science/op66595.html</a>.  And simply attached to a camera, to generate graph from.