Hi all,
I have been wanting to build a spectrometer for some time now, and few circumstances seam to have come together to finally get me to start. Firstly i came across Christian Buil's excellent description of how to build one, which gave me the confidence that this can actual be done by someone other than a specialist. Secondly, our laboratory was decommissioning (i.e. scraping!) our old ICP-OES (inductively coupled plasma-optical emission spectrometer, used for measurement of metals in water). Luckily i managed to get the two gratings out of the machine (and heaps of photomultipliers!) before it was sent to the recycling plant. However, i realized on inspection of the grating that it is not the conventional flat grating but concave/parabolic (not sure weather holographic or ruled). This seams to complicate things a little from that given by Buil, as from what i have read there are a number of different types of concave gratings. I'm pretty sure one of the gratings (a UV grating i guess because it only diffracts purple colours) is a rolands type, and so not very interesting for me. However, with the other one i am really unsure. I was wondering if any of you guys/girls have experience with such gratings and can tell what king it is by the attached images? i have also been wondering if it is better to use the grating as a collimation or focusing optic. Any comments would be much appreciated, as i am a total beginner, owning my first telescope for just 1/2 a year now!!
I can speak and read German, but my writing is terrible, so please feel free to answer in German. Coming initially from Australia, i have been doing my best to learn German since living in Heidelberg and Braunschweig, but the writing still needs allot of improvement
Ben