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07 Apr 16:33 210,445 views | Last edited by Natalie about 1 month ago | shortlink

Mid stream Urine analysis: Check whether you need to drink more water or not

by chongyukwai 7 days ago | 4 | 319 views | 2

Background: This is an experiential application of using spectro as a measurement of the concentr...

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Internal Image of Desktop Spectrometer with "Gum Stick" Camera

by kbollhorst 30 days ago | 0 | 580 views | 2

I have posted an image of the "gum stick" camera version of the desktop spectrometer. I wish to a...

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The accidental raspberry pi spectrometer: first light

by khufkens about 1 month ago | 0 | 653 views | 2

I put my design together today. The design used is shown below, but has some issues still. Genera...

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can a surface sheen be collected for oil testing?

by mathew about 1 month ago | 1 | 552 views | 2

image by by Cesar Harada CC-BY-NC-SA Can an oil slick be picked up off the surface and concentra...

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curved grating

by DarkGreen 2 months ago | 2 | 647 views | 0

so... I use a blank DVD-R, and ofcause that makes the grating curved. Are there any software for...

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a history of crediting contributions

by mathew 2 months ago | 3 | 977 views | 3

photo credit @Stevie, Washington University students build camera rigs. Giving proper credit for...

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Link to: An introduction to the use of fluorescence spectroscopy in inorganic analysis

by Frikkie 2 months ago | 0 | 877 views | 1

This is some very useful info:

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Baffle for Spectrometer 3.0

by ke4rjg 2 months ago | 3 | 860 views | 2

Sometimes, scattered light can degrade the contrast of the spectrum, particularly if you are obse...

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More research on "spectrometer" »

Title Last edited Edits Pageviews Likes
Ottawa 2 months ago by warren 2 1,752 2
Spectrometry Sampling 3 months ago by OpenSourceScience 22 9,360 1
desktop spectrometry kit 3.0 3 months ago by Natalie 29 4,803 3
desktop spectrometer 3.0 parts list 4 months ago by mathew 2 3,025 1
Foldable Mini-Spectrometer 4 months ago by warren 19 60,964 5
Desktop Spectrometry Kit 5 months ago by MrBumper 42 42,539 7
Pesticide Detection Methods Development 7 months ago by silverhammer 27 7,667 6
The Homebrew Sensing Project 8 months ago by Becki 5 4,085 0
Oil Testing Kit 8 months ago by warren 74 11,199 5
Spectral Workbench API 8 months ago by warren 30 8,115 4
Oil Testing Kit Literature 8 months ago by mathew 5 1,725 1
Spectrometer construction 10 months ago by warren 6 19,511 0
Refinery Watching 10 months ago by warren 17 6,291 3
Spectrometer History 10 months ago by mathew 4 2,650 0
Oil Testing Kit Illustrations 10 months ago by warren 3 1,667 0
spectrometer-media 11 months ago by warren 2 3,431 0
How to make a homemade spectrophotometer 11 months ago by Haripriya 3 4,976 2
Smartphone spectrometer about 1 year ago by mathew 26 24,010 3
Spectrometer Curriculum over 1 year ago by bicwood 25 8,244 3
Spectral Analysis Techniques over 1 year ago by Markos 7 4,721 1
How Kickstarter backers will use the spectrometer over 1 year ago by Becki 4 7,423 0
Countertop Spectrometer over 1 year ago by warren 7 3,978 0
Spectrometry Meetups almost 2 years ago by liz 3 2,272 1
Suggested Spectrometer Readings almost 2 years ago by PeterDavidowicz 10 3,750 0
Spectral Challenge ideas almost 2 years ago by philippg 18 4,054 3
Spectrometry health applications almost 2 years ago by warren 10 3,848 1
DIYBIO Ideas and Applications about 2 years ago by briandegger 3 2,759 2
Spectral Challenge Teams about 2 years ago by warren 1 2,171 0
Spectral Challenge about 2 years ago by warren 30 6,161 1
Spectrometry FAQ over 2 years ago by warren 1 2,378 0

USB Desktop Spectrometry Kit 3.0

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