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28 Jul 14:27 133,347 views | Last edited by warren 4 days ago

Karen's comments on the spectrometer instructions

by mathew | about 2 hours ago | 0 | 4 views | 0

Karen assembled a desktop spectrometer and commented the instructions during our 7/31 workshop.

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Hardware design work for the Oil Testing Kit

by mathew | about 3 hours ago | 0 | 10 views | 1

A hardware sketch of our favorite configuration is above. _This is a jointly authored research no...

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Recap: July 31 New Orleans oil testing meetup

by stevie | about 3 hours ago | 4 | 20 views | 1

Last night we held a meetup (organized by Stevie) to work on the emerging Oil Testing Kit with fo...

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Equalizing area of spectral graphs for comparison

by warren | 2 days ago | 0 | 51 views | 2

What I want to do During the development of testing techniques with spectrometers in the Public ...

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Spec Cam to Infragram w/the flip of filter? (Rosco "Fire" #19)

by Natalie | 3 days ago | 11 | 108 views | 0

What I want to do I would like to see if the "low-cost" webcam we are using currently for our De...

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Accuracy of assembled Desktop Spectrometry kit?

by WhiteRabbit | 3 days ago | 7 | 86 views | 1

How accurate are the data plots produced by the Desktop Spectrometer Kit?

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Spectrometer on a chip

by WhiteRabbit | 6 days ago | 2 | 186 views | 1

I ran across this all-in-one chip while I was just now looking into filter wheels, and I thought ...

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Detection of Added Sugar in Red Wine Using Visual Light Spectroscopy

by ygzstc | 9 days ago | 12 | 549 views | 6

Introduction Naturally occurring sugar is the sugar found in whole, unprocessed foods, such as m...

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More research on "spectrometer" »

Title Last edited Edits Pageviews Likes
Oil Testing Kit 2 days ago by mathew 60 2,871 3
Desktop Spectrometry Kit 3 days ago by warren 37 26,130 5
Spectrometer construction 8 days ago by warren 6 12,737 0
Spectrometry Sampling 8 days ago by warren 21 5,670 1
Refinery Watching 8 days ago by warren 17 3,965 3
Spectrometer History 9 days ago by mathew 4 139 0
Oil Testing Kit Illustrations 9 days ago by warren 3 68 0
Foldable Mini-Spectrometer 14 days ago by warren 17 36,601 4
spectrometer-media about 1 month ago by warren 2 2,123 0
How to make a homemade spectrophotometer about 1 month ago by Haripriya 3 684 0
ottawa about 1 month ago by Haripriya 1 176 1
Pesticide Detection Methods Development 3 months ago by silverhammer 25 4,785 6
Smartphone spectrometer 5 months ago by mathew 26 11,458 2
The Homebrew Sensing Project 5 months ago by warren 4 1,590 0
Spectrometer Curriculum 6 months ago by bicwood 25 6,059 3
Spectral Analysis Techniques 6 months ago by Markos 7 3,197 1
Spectral Workbench API 8 months ago by warren 28 5,678 2
How Kickstarter backers will use the spectrometer 10 months ago by Becki 4 5,255 0
Countertop Spectrometer 10 months ago by warren 7 3,035 0
Spectrometry Meetups 12 months ago by liz 3 1,671 1
Suggested Spectrometer Readings about 1 year ago by PeterDavidowicz 10 2,888 0
Spectral Challenge ideas about 1 year ago by philippg 18 3,360 3
Spectrometry health applications about 1 year ago by warren 10 3,133 1
Spectral Workbench exporting about 1 year ago by warren 6 2,981 0
DIYBIO Ideas and Applications about 1 year ago by briandegger 3 1,945 2
Spectral Challenge Teams over 1 year ago by warren 1 1,559 0
Spectral Challenge over 1 year ago by warren 30 5,331 1
Spectrometry FAQ over 1 year ago by warren 1 1,774 0
Spectral Workbench offline over 1 year ago by warren 4 4,398 0
Spectrometer preorders almost 2 years ago by warren 1 1,281 0

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 is 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?



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