Diy Spectroscope: Difference between revisions

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https://www.exploratorium.edu/snacks/cd-spectroscope
https://www.exploratorium.edu/snacks/cd-spectroscope
https://edu.rsc.org/feature/build-your-own-spectrophotometer/2020107.article
* Nice! spectrophotometer

Revision as of 21:35, 4 January 2025

Introduction

Spectroscope. Spectrometer is the machine to give the readings.

Spectroscope can be made using

  • Diffraction grating; eg. CD or DVD disk, or
    • Natural gratings: Striated muscle, peacock feathers, mother-of-pearl, and butterfly wings. Some invertebrate animals, like the peacock spiders, the antennae of seed shrimp, and Burgess Shale fossils
    • Iridescence in birds, fish and insects is often caused by thin-film interference
  • Prism


Theory

Interference.

Spectral lines

See:

Diffraction

Prism

DIY

Below is collection of some tutorials.

CD (and DVD) consists of two layers that will split apart when cutting the disk. We will discard the reflective part (the one with the silver coating).

DVD: Cut out a section of the DVD and then carefully peel it into two pieces. Use the clear piece.

Two different models:

  1. Look-through
  2. Use the reflection: Put the CD with the shiny side facing upward into the slit.

Both will have the slit where the light source enters the spectroscope. If this slit is too large, it can affect the clarity of the spectrum.

  • Use two razorblades to make the slit, and put one sheet of paper in between the blades to get correct spacing.
  • the concentric grooves along the disk are lined up such that they are parallel to the slit. Otherwise, no diffraction.


CD and DVD and a paper tube. Paint black.

Diffraction grating

References

https://mpr-projects.com/index.php/2024/05/23/building-a-diy-spectroscope-video/

  • Use "an analogue pocket spectroscope".

https://www.instructables.com/DIY-Low-Cost-Spectrometer/

  • Good stuff.
  • Slit, CD grating etc.
  • Adjust the position of the webcam till the diffraction spectrum is positioned in the center of the image.

https://www.exploratorium.edu/snacks/cd-spectroscope

https://edu.rsc.org/feature/build-your-own-spectrophotometer/2020107.article

  • Nice! spectrophotometer