DIY Spectrometer with Just a Webcam and Common Household Items
Technovation's low-cost device uses cardboard, black chart paper, an old DVD disc, razor blades, glue, and tape.
With lab sessions largely suspended over the last year, especially for students, accessible and reliable lab instruments are necessary to allow at-home experimentation. As a part of an education in science and engineering, lab sessions provide a valuable chance to produce tangible results that clarify concepts in a way that relying only on lectures cannot. Unfortunately, the equipment required for most experiments, especially at higher levels of education, is complex and highly expensive. That’s why Technovation has posted their design for a low-cost spectrometer.
Spectrometers are useful in a large number of experiments, and this clever project uses a webcam — the only expensive component — along with cardboard, black chart paper, an old DVD disc, razor blades, glue, and tape. To make it, you first create an enclosure for the webcam using cardboard and black chart paper. While it is possible to use any kind of box, it may work better to make one fit the dimensions of the webcam you’re using. The rear face will have a slot to pass the webcam’s cable through, and the front face will have a slot the height of the camera lens. This is then turned into the entrance slit of the spectrometer by taping the razor blades over the gap.
The DVD is what makes the diffraction grating — what is going to split the beam of light according to wavelength. You could also purchase one, but to transform an old DVD, just cut it into the disc until you can split its layers apart and discard the silver coating. Then you can cut the rest into a small rectangle a little bigger than the width of your lens and glue it on.
This gets you all the basic hardware you need. When connected, the spectrometer will produce an image of the spectrum. This doesn’t provide much information on its own, but the project’s designer has also created a program in Python to plot intensity, with the code available via GitHub. All made by an undergraduate physics major, the project is both a great example of a new generation of scientists producing solutions to their own unique set of problems and a great experiment for anyone interested in physics at home.
