DIY Spectroscopy

Abstract

An interesting item has been presented on eBay several times over the last few years, a Do-It-Yourself (DIY) complete system spectrograph referred to as a spectrometer. It is actually a misnomer to call these units DIY. They are complete and while one can do fine tuning and wavelength window adjustments, there is little else to do other than to turn on connect to a computer and take spectra. These units are refurbished, but appear to be in like-new condition. They sell for less than $200, about the price of the Star Analyser. More information on them can be found on the Science-Surplus.com web site at http://www.science-surplus.com. The site indicated an aligned unit is $500, however, the three units tested were purchased for $200 each and were all aligned well. In addition, if a unit needs alignment, the procedure is not difficult. The web site also indicates discounts to educators. At under $200 many interested astronomers purchased these units. Most of the spectrometers come with an 1,800 l/mm grating. Some units come with a 900 l/mm grating. The ones with the 900 l/mm grating sold for $299, but otherwise are identical to the 1,800 l/mm grating spectrometer. Additional gratings can be purchased for $75.00 (Table 4.1).