DIY spectroscopy
Over the next few months our research takes us into the realm of DIY spectroscopy, the ‘study of the interaction between matter and radiated energy’. Light, generated by a flame, LED or star for example, can be split into its composite ‘spectra’ and from this, its composite elements can be detected, like an elemental fingerprint.
We are interested in using this as a tool for testing water quality, and ultimately making new sounds, building on the instruments we developed for flow. We are aiming to develop a decent tool, which can detect and sonify subtle differences, in water quality. To do this white light can be transmitted through a water sample, by looking at which wavelengths or colours of light are absorbed; it is possible to detect things like pollutants.
It is simple to make a DIY spectroscope loads of DIY versions online for exapmple, using a DVD as the diffraction grating to break up the light, an accurate and narrow slit can be made with carful placement of tape or foil or better still using razor blades as a rectifier for the beam. Refining the optics takes a bit more work. Our volunteer came in to do some experiments using a phone as a spectroscope using basic materials; the results were quite interesting, fairly good considering the basic materials.
Above. One of the best results transmiting light through a salt water sample.
There are a huge amount of resources and instructions available online, the best resources can be found through the Public Labs Publiclabs.org project ‘Spectral Work Bench’ including useful kits and plans and instructions to turn your phone into a spectroscope, most impressive and useful is a Chrome based interface, for use with a web cam based digital spectroscope [which they also provide plans kits for] it analyzes the colours in the image, in real time, allowing you to save, share and compare your results. Brilliant.
Turn your smart phone into a spectroscope
http://i.publiclab.org/system/images/photos/000/001/393/original/smartphone-spec-instructions-p1-1.0.pdf
http://publiclab.org/notes/warren/6-12-2012/mobile-android-version-spectral-workbench