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Spectrometer

02 Jul 16:07 233,557 views | Last edited by warren 2 months ago | shortlink

Some Suggestions for Spectrometer v3.0 and Oil Testing Kit (OTK) Attachment

by ygzstc 12 days ago | 2 | 424 views | 2

I just wanted to share some ideas and suggestions for improving the stability of the spectrometer...

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Prototyping simple paper connections

by warren 16 days ago | 0 | 384 views | 1

What I want to do I'm thinking about easy to make and easy to manufacture paper linkages that re...

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Wavelength range limiting in Spectral Workbench

by warren 25 days ago | 0 | 377 views | 0

Just a quick announce -- after the big revision of Spectral Workbench went live last week, I also...

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Oil Testing Kit Public Beta Program - Welcome!

by ygzstc 26 days ago | 0 | 580 views | 3

We've had a huge response for our call for help in the Oil Testing Kit Beta Program from a couple...

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Sneak preview of new Spectral Workbench sets display

by warren about 1 month ago | 0 | 369 views | 0

Check it out here: http://spectralworkbench.org/sets/show2/2446 And see the embed here:

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Silhouette Cameo desktop paper cutter for prototyping

by warren about 1 month ago | 4 | 397 views | 1

What I want to do I've been wanting to do more laser cutting to prototype things like the Oil Te...

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Musings: Spectrometer Stability

by stoft about 1 month ago | 11 | 686 views | 2

My experiments with the PLab 3.0 spectrometer and PLab oil-test kit prototypes demonstrated the r...

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447nm Oops!

by scottvr about 1 month ago | 2 | 604 views | 2

Careful with even the backscatter from 1000+mW Watching my laptop screen, smelling something bur...

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More research on "spectrometer" »


Title Last edited Edits Pageviews Likes
Oil Testing Kit 6 days ago by mathew 121 14,322 5
Oil Testing Kit Beta 6 days ago by gretchengehrke 21 1,283 0
Oil Testing Kit Construction 28 days ago by warren 9 820 0
Desktop Spectrometry Kit 3.0 about 1 month ago by warren 43 9,745 4
Desktop Spectrometry Kit 2 months ago by warren 46 44,999 8
Spectrometer construction 2 months ago by warren 7 21,214 1
Desktop Spectrometer 3.0 parts list 2 months ago by warren 3 5,309 2
Ottawa 5 months ago by warren 2 2,561 2
Spectrometry Sampling 6 months ago by OpenSourceScience 22 10,207 1
Foldable Mini-Spectrometer 7 months ago by warren 19 69,084 5
Pesticide Detection Methods Development 10 months ago by silverhammer 27 8,448 6
The Homebrew Sensing Project 11 months ago by Becki 5 4,801 0
Oil Testing Kit Literature 12 months ago by mathew 5 2,353 1
Refinery Watching about 1 year ago by warren 17 7,020 3
Spectrometer History about 1 year ago by mathew 4 3,488 0
Oil Testing Kit Illustrations about 1 year ago by warren 3 2,191 0
spectrometer-media about 1 year ago by warren 2 3,765 0
How to make a homemade spectrophotometer about 1 year ago by Haripriya 3 6,155 2
Smartphone spectrometer over 1 year ago by mathew 26 28,112 3
Spectrometer Curriculum over 1 year ago by bicwood 25 8,934 3
How Kickstarter backers will use the spectrometer almost 2 years ago by Becki 4 7,930 0
Countertop Spectrometer almost 2 years ago by warren 7 4,294 0
Spectrometry Meetups about 2 years ago by liz 3 2,519 1
Suggested Spectrometer Readings about 2 years ago by PeterDavidowicz 10 4,022 0
Spectral Challenge ideas about 2 years ago by philippg 18 4,379 3
Spectrometry health applications about 2 years ago by warren 10 4,048 1
DIYBIO Ideas and Applications over 2 years ago by briandegger 3 3,024 2
Spectral Challenge Teams over 2 years ago by warren 1 2,393 0
Spectral Challenge over 2 years ago by warren 30 6,508 1
Spectrometry FAQ over 2 years ago by warren 1 2,579 0

Desktop Spectrometry Kit v3

The standard -- plugs into your laptop

Build one Buy one

Smartphone Spectrometer

Rigid plastic version which attaches to your smartphone

Build one Buy one

Foldable Mini-Spectrometer

Cheap, easy, starter version for smartphones and webcams

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:

sky.png


Types of spectrometry

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

Fluorescence

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.

See the lead image of this page for a diagram of a fluorescence spectrometer setup. 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 »


IMG_20140722_230007_2.jpg

Emission

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

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 links at the top of the page offer step-by-step instructions on making your own spectrometer. Our main design, the Desktop Spectrometer, features:

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

Upgrades

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 the Upgrades section of its documentation.


Screen_Shot_2014-07-24_at_3.44.28_PM.png

Software

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

FAQ

Frequently Asked Questions can be found here »

Challenges

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:


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.

Kickstarter

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.

knight-logo


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