###Introduction### The PLOTS Spectrometer is a tool Colin Frazer and Jeff Warren have been developing at RISD's Environmental Justice research group. A spectrometer is a tool for identifying the unique patterns of light refracted, reflected or emitted from an object, like a fingerprint. Using spectrometer you can collect that pattern of light and use it to identify what a substance is made of.  We hope to use spectrometry to identify harmful gases emitted during the course of oil and gas production. Our spectrometer consists of a cardboard box, a broken CD, and a digital camera. The cardboard box or tube collects the light from an object. The broken CD splits that light into a rainbow like spectrum. The digital camera photographs that spectrum so we can analyze it using our online tools. ###Analysis: Interpreting your spectra### We've created an online analysis tool to upload your spectrometer photos for interpretation. All of this is very prototoype-stage, and we haven't yet identified a material based on the spectra it generates. However, as our first goal, we're interested in identifying **PAHs** (Poly-Aromatic Hydrocarbons) (which are present at the [Gulf Coast](/place/new-orleans) and the [Gowanus Canal](/place/new-york-city), and **benzine**, which is amongst the contaminants found at natural gas extraction sites, especially those employing hydraulic fracturing. http://spectrometer.publiclaboratory.org The spectrometer has also been the subject of a public workshop by Jeff Warren and Nadya Peek at [Escuelab](http://escuelab.org) in collaboration with [FabLabLima](http://fablablima.org) in Lima, Peru: http://publiclaboratory.org/report/diy-spectrometry-workshop-lima-peru An alternative set of instructions not requiring PVC or razor blades: here