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How to make a homemade spectrophotometer

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  • 2 pieces of Thin Cardboard (9.5cm x 14.5cm and 6cm x 20 cm)
  • Corrugated cardboard (21cm x 10cm and 20.5cm x 11cm)
  • Camera
  • Empty CD (radius: 5.3cm)
  • Elastic band
  • Flashlight
  • 3 pins
  • Popsicle stick – 7 cm
  • Shoebox (20.5cm x 13cm x 11cm)
  • Styrofoam (29.1cm x 20cm x 9cm)
  • White paper (1 sheet)


  1. Fix the flashlight horizontally in the Styrofoam. Cut a hole so that only the bulb of the flashlight is exposed and rest of the head is covered.
  2. Cut a hole on the side of the shoe box in such a way that it lines up with the hole in the Styrofoam.
  3. Cut a slit in the 20.5cm x 11cm corrugated cardboard. Line this up with the hole on the side of the shoe box, with just enough gap to keep the transparent cup between the shoe box side (with hole) and the slit on the cardboard.
  4. Place the cup with the center lining up with the slit on cardboard and hole on shoe box side, touching the side. Put the elastic band over the box with a pin on corrugated cardboard, to keep the cup in the center and in the correct position. Use the other two pins to mark the position of the cup.
  5. Cut 1/8 of a CD. Take the 45 degree wedge and glue it to the piece of thin cardboard. Take it and tape it to an adjustable ring around the piece of corrugated cardboard (21cm x 10cm).
  6. Cut a flap on the side of the box where the light will come through. Cover the thin piece of cardboard (9.5cm x 14.5cm) with a piece of white paper. Tape it to the flap. Tape a Popsicle stick to the back of the cardboard. You should be able to re-adjust it
  7. Put the cardboard with the CD wedge at about 60⁰ angle facing the flap. The bigger part of the wedge should be closest to the flap. Cover the inner side of the shoe box and its lid with black paper.
  8. Put the Styrofoam right next to the box so that the holes lineup. Put the lid on the shoe box and turn off the lights. Turn on the flash light inside the Styrofoam. Adjust the CD and the flap so that the full spectrum image from the CD can be clearly seen on the flap. Position the camera to take focused spectrum image on the flap.