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16 Nov 17:43 164,768 views | Last edited by warren 7 days ago

a paper spectrometer design

by mathew | 16 days ago | 6 | 443 views | 2

What I want to do build a spectrometer that doesn't use a conduit box, out of mostly paper and c...

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CFL detection by contrast, for auto-calibration

by warren | about 1 month ago | 0 | 355 views | 0

What I want to do I was thinking we might be able to do a crude but very fast CFL detection by m...

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Passing Light Through an Object.

by amysoyka | about 1 month ago | 0 | 401 views | 1

What I wanted to do Related Posts:

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Spectral Workbench previewing and clipping warnings

by warren | about 1 month ago | 1 | 759 views | 2

Just a quick update here - I added a webcam preview to the capture interface (see above) as well ...

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Quantifying reflector brightness assistance

by warren | about 1 month ago | 1 | 310 views | 1

What I want to do At the New Orleans oil testing meetup, started using reflective foil mylar (li...

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shorter spectrometer geometry with two slits?

by mathew | about 1 month ago | 3 | 507 views | 2

What I want to do answer two questions: Can straylight be eliminated in a simple spectrometer se...

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PVC Pipe Fitting Modification to 3D Printed Body

by bsugar | about 1 month ago | 1 | 569 views | 2

Special thanks to a friend at my local hometown library for her help in making this possible, and...

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A Lil' Box for the Oil Testing Kit. (Incomplete)

by amysoyka | about 1 month ago | 7 | 387 views | 3

Oil Testing Kit from a sheet of A4 Paper? (kind of...) Sometime ago, @warren and @mathew were tr...

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More research on "spectrometer" »

Title Last edited Edits Pageviews Likes
Desktop Spectrometry Kit 7 days ago by warren 40 32,676 5
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Pesticide Detection Methods Development 11 days ago by silverhammer 27 5,768 6
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Oil Testing Kit Literature 2 months ago by mathew 5 681 1
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Oil Testing Kit Illustrations 4 months ago by warren 3 634 0
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USB Desktop Spectrometry Kit

Build one Buy one

Smartphone Spectrometer

Build one Buy one

Foldable Mini-Spectrometer

Build one Buy one

Public Lab's Do-It-Yourself spectrometers are designed to help everyday people detect pollutants where they live.

Our community has been working since the 2010 Deepwater Horizon oil spill to develop a cheap, open source, Do-It-Yourself spectrometer which we hope to use to identify oil pollution in soil and water, as well as a range of other possible contaminants.

What's spectrometry?

Colored light is often a blend of different colors. A spectrometer is a device which splits those colors apart, like a prism, and measures the strength of each color. A typical output of a spectrometer looks like this spectrum of the daytime sky, with the actual light spectrum at the top and the graph of wavelength (horizontal axis) and intensity (vertical axis) below:


Types of spectrometry

There are different ways to use spectrometers, and the key difference is how you illuminate your sample.


This project focuses on fluorescence spectrometry in order to identify oil pollution samples, which is where a high-energy light like an ultraviolet laser is used to excite a sample so that it fluoresces, or glows.


Since different oils fluoresce in different colors, this technique can be used to match an unknown sample with a reference sample to identify it.

Read more on the Oil Testing Kit page



Emission spectroscopy is the kind often done in the classroom, where burning a material emits a colored flame. A spectrum of this colored flame can be used to match a material, but it can be unsafe to burn unknown samples, so we have primarily begun to use this technique to attempt to monitor distant flares, for example at gas refineries in Louisiana, to try to detect heavy metals.

[image of refinery watching]


Absorption spectroscopy -- shining a full-spectrum light like a halogen or incandescent (not a fluorescent or laser) through a sample to see what colors are absorbed -- is a bit more difficult in the visible light range, as most of the "fingerprint" features of spectra are too long or too short wavelengths for our webcam-based devices. However, a considerable amount of work has been done on absorption spectrometry of:

Make a spectrometer

The Public Lab Spectrometer is a Do-it-Yourself device made from simple materials:

  • stiff black card paper
  • a clean DVD-R
  • a USB webcam (preferably HD)
  • a Type LB conduit body (basically a light-proof box with a couple holes)
  • double-sided foam tape and a box cutter/x-acto knife

The DVD's tightly packed grooves act as a diffraction grating -- like a prism.

Spectrometer construction »

The above link offers step-by-step instructions on making your own spectrometer. It features:

  • around 400-900 nanometer range, maybe wider (what you can see with the naked eye, plus some infrared)
  • 5-10 nm spectral resolution
  • 20-30 samples per second
  • ~ $15 in materials
  • < 1 hour construction time
  • open-source software

Though these specs look pretty good, they still need to be compared rigorously with a traditional laboratory spectrometer. Are you interested in trying it?


Once you've built a spectrometer, there are many ways to improve it -- by using a narrower slit, darkening the interior, using a better camera, and more.

For upgrading the USB webcam-based Desktop Spectrometry Kit, see



Along with the physical devices, the Public Lab community has also developed Spectral Workbench, an website to capture data with your spectrometer, analyze and compare spectra, share them in an open database, and comment and collaborate with others.

The software includes:

  • direct connection to your USB-based or smartphone-based device
  • calibration, comparison, and matching tools
  • XML, JSON, and CSV data download
  • a JavaScript API
  • offline mode
  • read more in the documentation


Frequently Asked Questions can be found here »


This document, and this methodology, is still under active development. What you see on this page is only the best attempt so far at collating and presenting the work of Public Lab contributors to date. Some of the challenges that remain include:


Along with the physical devices, the Public Lab community has also developed Spectral Workbench, an website to capture data with your spectrometer, analyze and compare spectra, share them in an open database, and comment and collaborate with others.

Other uses

While many of us have focused on identifying oil pollution with fluorescence spectrometry, there are many other uses for cheap, open source spectrometers, and many other ways to use a spectrometer.


In 2012, Public Lab ran a Kickstarter project to distribute an early version of our DIY spectrometers to over 1600 people. The video is a bit out of date, but is still a compelling way to understand what we're attempting to do:

The Homebrew Sensing Project is made possible in part by the generous support of the John S. and James L. Knight Foundation, Knight News Challenge: Health.


Tags: spectrometer list:plots-spectrometry tabbed:notes tabbed:wikis tool