Making a spectrometer: help needed

Discussion in 'Supporting Physics' started by Helen Jones, Dec 6, 2017.

  1. I've been making a hand spectrometer, as outlined on CLEAPSS, with some success.

    The hardest part of the process is stripping the printed surface off the CD / DVD, so that I can use the transparent disc as my diffraction grating. I've been peeling the print off with duct tape, with patchy results. Does anyone have any tips for a better way to clean off a CD / DVD please? Our physics teacher liked the end result, so I may need to make a class set in the new year...

    Thanks,

    Helen.
     
  2. are you using a DVD-R disc?
    I managed with a fair amount of success, using scissors, cut the disc into quarters and then finding a peelable edge.
     
  3. I have one, there was no need to strip anything off it to get it to work. Works best with a DVD. We bout a cutout plastic holder you fold and slide the DVD in. In ours the DVD stays whole.

    I have been trying to get some enthusiasm up with our Physics staff to use diffraction to work out the spacing on the disc but they don't seem keen on moving away from the curriculum.
     
  4. I currently have a couple of old CDs from home - e.g. old 'educational' discs for the computer from when the kids were little. They are proving very stubborn!
     
  5. surely these are spectroscopes not spectrometers?
     
  6. Drat, I think you're right. Still struggling with getting the opaque coating off. I've got most of the ink off with sellotape now, but the underlying reflective silver backing is proving more stubborn.
     
  7. still don't understand why you need to remove anything, you just need to hold the disk at an angle for the light to strike it, you then view from above.You can clearly pick out the black lines in the spectra.
     
  8. Helen, are you refering to GL143 on CLEAPSS that uses a mobile phone? If so where does the CD/DVD come in?

    I'm asking as I'd like to make the one shown in the above guide.

    Thank you.
     
  9. Thanks Nick for the link - that looks like it's worth trying. Hands, it is the GL143 - it has the advantage of being able to photograph the spectrum with the phone, so that the teacher can put the various spectra seen up on a big screen for students to compare, but does need the CD stripped as it relies on light passing through the thing into the camera, rather than viewing by eye within a box. Will definitely try out the box version though, once back at work next week - snow permitting!
     
  10. Thanks Helen. I'm assuming the stripped "film" from the CD takes the place of the diffraction grating.

    I look forward to giving this a try in the not too distant future.

    Edited to say: looking at your original post I think I may have got the wrong end of the stick and it's actually the stripped disc that's needed.
     

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