Share this project


Share this project

This DIY kit helps analyze materials and contaminants. We need your help to build a library of open-source spectral data.
This DIY kit helps analyze materials and contaminants. We need your help to build a library of open-source spectral data.
This DIY kit helps analyze materials and contaminants. We need your help to build a library of open-source spectral data.
1,633 backers pledged $110,538 to help bring this project to life.

#SpectralChallenge prize for open spectrometry, new store, and more!

Hi! Liz from Public Lab here today... first off, updates on the last few rewards: 

  • All domestic and Canadian countertop orders have been shipped! International orders are awaiting 240v compatible parts and final assembly.
  • The smartphone “Mobile Spectrometers” are about to enter production, just waiting on the final prototype to be printed and last-minute checked.

Announcing #SpectralChallenge

Looking for something to do with your spectrometer? Spectral Challenge is an X-Prize-style call to makers, hackers, and Do-It-Yourselfers worldwide to tackle real-world environmental problems with low-cost, open source spectrometry. We are hosting a crowd-funded prize for community researchers who want to make DIY spectroscopy better, starting with a Stage 1 prize for improving open spectrometric methodology, and a Stage 2 prize for identifying a pollutant in your neighborhood. Entries are now open, and teams are starting to form -- check it out at

Announcing the Public Lab Store

Missed out on the first round, or want more? Our store -- carrying the now $40 DIY Spectrometry Kit and the Foldable Mini-Spectrometer -- is now taking orders: check it out at and follow the link to see all things spectroscopy!

Spectral Workbench API

The Spectral Workbench API is getting a boost with a new system for sharing macros -- As always, anyone who can code JavaScript and/or Ruby on Rails is welcome to join in the coding, it's all open source.

Finally, your fellow spectral enthusiasts are talking and doing up a storm on the Public Lab spectroscopy group. There’s a thread about making a bulk purchase of sampling containers -- like petri dishes, polystyrene cuvettes and caps, optical grade sample bottles, evidence bags, and similar items -- so weigh in if you’d like some or know a good supplier with bulk pricing.

Happy analyzing! See you online at the Public Lab spectroscopy group.

  • Image 228868 original

Quick update about last few rewards

Hello all -- quick update on the last few rewards. We didn't quite make the February ship date we expected, but completed Countertop models are now piling up around our workspace, and we're waiting for the last few bits -- sample containers, label stickers, and so forth. They are being calibrated and packed, so we should be shipping out the first batch by the end of this week if all goes well. Sorry for the delay and we hope that'll put us at only one week past the estimated ship date!

International countertop orders will take a little longer, since we are trying to source 220V light bulbs and figure out how to get plugs for any given country. What we may do is ship them with a fairly universal plug like the type that's on the back of most computers, and ask you to bring your own local plug (perhaps we can ship a European standard plug in each box in case you have an adaptor for that pretty common plug). If you have strong opinions about it, or suggestions, please leave a comment here!

We have pretty much finalized the Mobile Spectrometer, and Brad Dudenhoffer has posted a great update:

We were struggling for a bit to figure out how to provide a way to temporarily attach the Mobile Spectrometer to your phone, but have settled on a few options, one including Glue Dots (small, restickable and remarkably strong adhesive dots). We also tried some wacky solutions, like using the glue that's used to stick climbing skins to telemark skis (I happen to be a telemark skier). That last one worked all right, actually! But it was a bit messy:

Anyhow, just want you to know that we're hard at work finishing these off; they are looking amazing and we'll post another update as they start to ship. Thanks!

Here are a few more photos of the Mobile Spectrometer attachment tests: 


Here's me load-testing the double-sided removable foam adhesive: 

One more quick addendum -- we're being careful to choose a type of plastic that minimizes environmental and human health impacts -- but also that absorbs infrared light, and reduces reflection inside the device. I had to use one of our modified infrared cameras to confim this with a range of plastic samples, which ended up looking pretty neat. Read more here:

Countertop and Mobile Spectrometers and iOS progress

1 like

February is here, and soon so will the last few rewards! I know all of you who haven't gotten your rewards are eager to hear an update, so here goes:

Countertop Spectrometers

I've been working with Cort from Somerville to source and spec these all out and we believe we are on schedule to have them assembled and shipped by the end of February (knock on wood). We are working hard to be sure that they are durable, precise, and nice to look at and use. You can see some of our prototypes here.

Backpack, or Mobile Spectrometers

Brad Dudenhoffer and I have been working together on the injection moldable "backpack spectrometer" for your smartphones. We're now calling it the "Mobile Spectrometer" and progress has been fast and exciting. Below you can see a 3d printed version which we made on (for ~$50 -- we'll be releasing it soon too for purchase on Shapeways) and as you can see it looks gorgeous. Very Star Trek! Brad has been flexing his 3D modeling skills to make it injection moldable and we are optimistic about the timeline. Read more about Brad's work -- and get involved in the design process -- at his recent post on the Public Lab site.

We will post more as soon as we know details but we'll be working with

Steampunk spectrometers & iOS update

Photos coming soon of the steampunk specs (we found an imaging chamber that reminds us of Iron Man... or is it Wild Wild West?) but we know you're also eager to hear about the iOS native port of the software. Using PhoneGap/Apache Cordova and Adobe's PhoneGap Build, we've released the very first (and decidedly NONFUNCTIONAL) test build of our iOS/Android native app (iOS only works on registered devices, as per Apple's rules). Our goal is to release a still-photo version first, followed later by a live video version, which will involve some lower-level Objective C coding.

If you are interested in collaborating on the iOS build, which is open source, please get in touch! Specifically we need to begin accessing the live video feed without queueing the video "widget" -- a challenge on iOS. Source code is currently here:

Please post here or to the spectrometry mailing list with questions!

Quick revision to Desktop Kit instructions!

A follow-up -- the print instructions which shipped in the Desktop Spectrometry Kit ($35) contain a small error; they show the webcam being focused to 3" away, but in fact that distance should be 9". The online instructions have been revised and if you've already built your spectrometer, it's not hard to change. (download a revised PDF here) Your spectra should come out much sharper! Something like this:

(example by contributor seekerdave) Thanks to contributor ckmurt for catching this issue!

Also, full instructions with build photos and lots of helpful troubleshooting tips are coming together now on the Desktop Spectrometry Kit wiki page. Check it out!

Thanks and sorry for the trouble!

--The Public Lab staff

Spectrometers arriving: what next?

All but 64 of the Desktop Spectrometry Kits are now shipped, and from the buzz on twitter and the new spectra being uploaded to, many have already received, assembled, and begun to use them. As you get started with your kits, here are some useful links:

Remember, you are the vanguard -- the bleeding edge early adopters -- so as much as you can expect others to help you out, you should try to help each other debug and troubleshoot your spectrometers. We have a FAQ wiki page to add common issues to and if you find software issues you can post them on Github.

For the next weeks and months, we expect a lot of people to be just getting online with their devices, calibrating them and getting used to them. But once your spectrometer is calibrated and configured...

What next?

That's the question, really, that we hoped to answer by launching this project. We are far from having a mature, rigorous, credible scientific device, and we need everyone to pitch in to make progress. Some open questions include:

  • how best to scan liquid, gas or solid samples
  • what kind of lights to use; halogen, xenon, LED, laser, or UV?
  • how to detect faint light, like when putting samples in flame
  • how to compare data between different instruments
  • how to match an unknown spectrum to a known library of samples

What's important here is that we solve these problems together -- which means posting your work, images of your setup, and explaining your goals -- ideally on the community website. Its DEPRESSING to see data being uploaded without any explanation or background!

Problems to solve, ideas to explore

The above problems all have to do with the engineering and methodology, but what about use cases? Luckily, we asked you all to describe what you hoped to do with your devices in our survey, and we've posted most of those responses here, sorted by topic:

They include such diverse applications as:

  • Measuring output of LED arrays for a NASA-funded project for growing plants inside extraplanetary habitats
  • Solar cell efficiency
  • Maybe see if the color of campfire flames can reveal contamination (flame spectroscopy with a marshmallow)
  • Test the water in Greenpoint!
  • Compare soil samples for gardening
  • Testing springs along the Appalachain Trail
  • Testing whiskey, maple syrup, bananas, etc
  • Analyze alloys and compounds for home forge/foundry
  • Measuring colors of flowers
  • Blood analysis
  • Identify plastics for recycling through 3D printer
  • Use with my telescope on stars
  • Analyzing gasoline engine deposits and by-products
  • Make an Android app resembling a tricorder
  • Top Secret! (ed: hey, what about open source?)
  • Taking over the world!
  • Showing off to girls, that sort of thing

There are hundreds of ideas on the list... these just the tip of the iceberg! Really, check them out, they're super interesting -- and of course reach out on the spectrometry discussion list to find others who share your interests. This is only going to work if we work together, and open source what we do!

Beta beta

Finally, keep in mind that although we've put an enormous amount of effort into this project, it's still fairly experimental! The software is usable but may not have all the features or nicities we hope will be added. (It IS open source, however -- if you can help develop, please join in at We now have a Twitter account for Spectral Workbench code updates: follow @SpectralWB So be patient, work with us to refine and improve it, and make constructive suggestions!