The Desktop Spectrometry Starter Kit (now at version 3.0) is our most recent “reference design” incorporating some community improvements while balancing low cost and relative ease of construction. The DSSK was originally created as part of the Public Lab Spectrometry Project’s goal of identifying suspected oil residue after the BP oil spill.

We have not yet met all our intended goals for this design, which is still being refined by contributors like you. Explore its capabilities in the Activity grid, and post your own for others to try. Improve on this design by (for example) adding a sample holder or attaching a light, and contributing to the Additions & Modifications section section of the main spectrometry page.

• Capabilities
• Limitations and goals
• Plans
• Parts list
• Get involved in the next revision

Capabilities

Many basic improvements or additions can improve the capabilities of the DS3. But with the starter kit alone, you should be able to:

• Measure spectra with ~3 nanometer resolution (help refine this)
• Measure light from 400-700 nanometers (roughly the range of human vision) or more if you upgrade your kit

Can you propose an experiment to provide a better answer?

Limitations & Goals

Because most webcams’ exposure compensation cannot be disabled, we don’t know if or how much colors have been “boosted” between different photos. Because of this, you can compare spectra taken with the same device, but you can't necessarily compare between different devices -- but this is a challenge we’re working towards (see gain calibration in the grid below).

Note: If you are working on an urgent issue such as a threat to your or someone else’s health, please know that these techniques may not be ready for your use; it's possible that they never will be. Read more here

Add limitations here in the form of questions like "How can we correct for gain compensation in webcams?" so that others can propose solutions. Propose a solution, upgrade, or new feature yourself by first posing the question it addresses:

Ask a new question to explore further possible upgrades

Here are some which we'd like to adapt into question/answer format:

• Gain calibration: correct for the gain compensation of most webcams using a calibrated light source
• Improve the rigidity of the device: see rigidity upgrades
• Attach a light source and a sample holder to scan samples

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Activities

These are some activities specific to the Desktop Spectrometry Starter Kit -- for a full list of activities you can do with a DIY spectrometer, see the main Spectrometry page

Add your own activity Request an activity guide

Guides should include a materials list and a step-by-step construction guide with photo documentation. Learn what makes a good activity here.

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Upgrades

Have you added to your starter kit, improved it, or redesigned it? Show others how to take it to the next level by posting a build guide here:

Add your upgrade guide here Request or propose an upgrade

Mods should include a parts list and a step-by-step construction guide with photo documentation. See an example.

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Get involved in the next revision

As these upgrades mature, the Kits initiative will incorporate some into the Desktop Spectrometry Starter Kit itself (depending on cost & complexity) as part of our commitment to an open hardware design process

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Frequently Asked Questions

This section is for questions about the Desktop Spectrometry Starter Kit, specifically. For questions about spectrometry in general, see this FAQ.

Ask a question about the DSSK

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Table of contents & resources
Spectrometry wiki page | About our overall spectrometry program
Development history | How our spectrometer was collaboratively developed
Previous versions | Background on versions 2-2.5
Parts list | In case you want to to source parts on your own
Assembly | Instructions on putting this kit together
- - Bench
- - Assemble the box
- - Put it all on the bench

Plans

instruction_booklet_1.0-print-halfpage.pdf - Print a cleaned-up version of this page from a PDF

spectrometer3.0-instructions1.0-booklet.pdf - Print a booklet-formatted version from a PDF

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Parts List

• two-piece box

• JDEPC-OV04 "gumstick" webcam with USB cable. (Datasheet: Spec_of_JDEPC-OV04_Ver_1.01.pdf) -- note, this is not the same "gumstick" webcam as used in the 2.5 Desktop Spectrometry Kit.

  _Webcam is purchased in bulk from China. For more details E-mail kits@publiclab.org _

• extra paper for modifications

• 45 degree wooden (ash) camera block, 3 cm x 4 x 4cm

• wooden (ash) bench 1/4" (6mm) x 40mm x 235mm

  _Wood products are sourced locally in Portland, OR at Roeder Woodworking _

• one 65-degree fold up collimation angle

• one 45-degree fold-up camera angle.
• 50cm of 3/4" (2cm) width adhesive-backed loop fastener (Velcro-style)

• 25cm of 3/4" (2cm) width adhesive-backed hook fastener (Velcro-style)

  _We buy our velcro from McMaster Carr in bulk here. The two part numbers are 9489K21 and 9489K201 _

• one DVD-R

  We buy ours from Amazon, choosing the cheapest option at time of purchase

• photo emulsion printed slit 0.4mm wide printed on .004" acetate. (Design files on GitHub)

  Acetate is something made custom for Public Lab by Eberhardt Press

• 6 yard roll of 1/8" Thermoweb Supertape double sided tape. (3mm wide)

• printed assembly instructions (below)

Also see this longer illustrated parts list.

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Using your spectrometer

Once you've assembled your spectrometer and are ready to use it, plug it in and visit SpectralWorkbench.org to begin recording data with it. The web-based software works in the Chrome, Firefox and Opera browsers on most computers and smartphones.

(Peer) Support

Public Lab is not a corporation; we're an open community of DIY environmental science researchers which you have just joined! The best place to get help is the spectrometry mailing list; to join, sign up in the form to the left.

The spectrometry mailing list is made up of people like you, who are building and improving open source spectrometry techniques. Ask questions, look for help, and consider helping others too!

You can also post a question on this site; it helps to share some photos or screenshots of what you're trying to do:

Ask a question about spectrometry or Sign up to answer questions on this topic

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Assembly

Assembly instructions are now provided as a step-by-step activity; leave feedback and ask questions in the comments below:

Desktop Spectrometry Starter Kit 3.0 Assembly Instructions - by @mathew, @warren, and @abdul -- formerly hosted on this page.

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Design notes

Here are the series of notes printed on the spectrometer. Notes below by: @amysoyka, @straylight, @wagnerc4, @ygzstc, @cfastie, @stoft, & @Alex-McCarthy.

• lens focus: /n/7226
• grating angle: /n/5964 /n/5892
• spectrometer development history: /n/10691
• removable slit cards: /n/11246

Spectrometer development:

• calibration: /n/191
• linearity: /n/10476 /n/6225

Evolution

Consult the following notes on development for the evolution of this design:

• @mathew paper spectrometer 1
• paper spectrometer 2