Spectrometry
spectrometry

The Public Lab spectrometry project is an open source community effort to develop low-cost spectrometers for a range of purposes. All open spectrometry hardware and software efforts are welcome here! **Join in by:** * Learning [what spectrometry is](#Whats+spectrometry) * Reading about goals and [asking great questions](#Frequently+Asked+Questions) * Building a basic spectrometer using [one of our starter kits](#Starter+Kits) * Trying (and critiquing) our [community-made how-to guides](#Activities) and posting your own * Building on others’ work; hack and remix the kits to refine and expand them * [Share your upgrades](#Upgrades) for others to try -- and perhaps for inclusion in an upcoming starter kit release or add-on kit **** ## Starter Kits Public Lab’s Kits initiative offers several starter kits, including many of the basic components, and instructions for constructing a basic visible light spectrometer. The point of the kits is to provide a shared reference design for building experimental setups onto. Lego Spectrometer Kit Our most recent kit, incorporating community improvements while balancing low cost and ease of construction. Choose between webcam and Raspberry Pi camera versions and build attachments width standard Lego connectors. Build one Buy one Papercraft Spectrometry Intro Kit A $9 paper spectrometer which you can attach to a smartphone or webcam. It’s made of paper to reduce cost and complexity, and is mainly intended as an “introductory” or educational kit. The flat design can be printed on a laser printer or photocopied to make more. Build one Buy one **** ## Activities This is a list of community-generated guides for specific applications using your spectrometry setup (either a [starter kit](#Starter+Kits) or a [modded design](#Upgrades)). These [activities can be categorized](https://publiclab.org/wiki/activity-categories), and some may be more reproduced -- or reproducible -- than others. Try them out to build your skills, and help improve them by leaving comments. Together, we can repeat and refine the activities into experiments. > **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](/notes/gretchengehrke/09-29-2016/common-low-cost-technique-limitations) ### Activity grid [activities:spectrometry] **** ## 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: [upgrades:spectrometry] 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._ **** ## Challenges We're working to refine and improve DIY spectrometry on a number of fronts; here, take a look at the leading challenges we're hoping to solve, and post your own. For now, we're using the Q&A feature, so just click "Ask a question" to post your own challenge. Be sure to add: * constraints: expense, complexity * goals: performance, use cases [questions:spectrometry-challenge] **** ## Builds There’s a lot going on in open source spectrometry -- if you’ve developed another open source design you’d like to show others how to construct, post it here! * [RamanPi](https://hackaday.io/project/1279-ramanpi-raman-spectrometer) * [Hackteria “drop”-style spectrometers](https://publiclab.org/notes/gaudi/04-03-2014/diy-micro-volume-spectrophotometer) / [DIY NanoDrop on Hackteria.org](http://hackteria.org/wiki/index.php/DIY_NanoDrop) * _Add yours here_ ##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, in nanometers of wavelength) and intensity (vertical axis) below: [![sky.png](https://i.publiclab.org/system/images/photos/000/005/455/original/sky.png)](https://spectralworkbench.org/analyze/spectrum/19882) > Needed: overview of spectra, calibration, units, comparison, and fluorescence/absorption. Please edit this page or link to a resource, potentially [the Wikipedia page](https://en.wikipedia.org/wiki/Spectroscopy), although that's quite full of technical jargon. ## Software Spectral data can be analyzed with https://spectralworkbench.org to create spectra plots, find centers of emissions plots, and find similar spectra. Data also can be exported in various formats (JSON, CSV, XML) for further analysis and visualization. ## How does this compare to a lab instrument? The [Desktop Spectrometry Starter Kit](/wiki/desktop-spectrometry-kit-3-0) is only one part in an experimental setup, and the following shows where it fits in an overall diagram of a lab spectrometric setup: [![tmp_31873-IMG_20161027_101601_2-79757779.jpg](https://publiclab.org/system/images/photos/000/018/635/large/tmp_31873-IMG_20161027_101601_2-79757779.jpg)](https://publiclab.org/system/images/photos/000/018/635/original/tmp_31873-IMG_20161027_101601_2-79757779.jpg) [![tmp_31873-IMG_20161027_095939_2-108076392.jpg](https://publiclab.org/system/images/photos/000/018/636/large/tmp_31873-IMG_20161027_095939_2-108076392.jpg)](https://publiclab.org/system/images/photos/000/018/636/original/tmp_31873-IMG_20161027_095939_2-108076392.jpg) There are many, many different types of spectrometry and spectrometers -- many don’t even measure light. Even among those that do, some detect light in the ultraviolet range, and others in the infrared range of light. The range of Public Lab spectrometers depends on the range of the commercially available cameras we attach them to (~400-700 nanometer wavelengths). A commercially available product with a slightly wider range (from 335 to 1000 nanometers) is [available from Cole Parmer](http://www.coleparmer.com/Product/Cole_Parmer_Visible_spectrophotometer_335_to_1000_nm_wavelength_range_analog_output/UX-83055-10). **** ## Frequently Asked Questions [questions:spectrometry] Note our previous Frequently Asked Questions page, which [can be found here »](/wiki/spectrometer-faq) -- please help port these into the new system, here!...


Author Comment Last activity Moderation
pablo "I've focuses to 22cm, removed blue LED: https://spectralworkbench.org/spectrums/91509 The blue hump is still there. I'll try to change the DVD to ..." | Read more » over 7 years ago
warren "I think the blue hump was something we saw a lot on those SYBA webcams, and believe it was related to a blue LED in the webcam itself, which you ca..." | Read more » over 7 years ago
stoft "I note that 1) your spectrum does "fit" though it is 2) "offset" a bit from center which is likely related to the angle. (Just to identify what is ..." | Read more » over 7 years ago
warren "I think you can use this old focus tutorial and do it empirically: https://publiclab.org/wiki/dsk#Unscrew+the+lens+and+remove+the+infrared+filter ..." | Read more » over 7 years ago
pablo "Thanks @stoft and @warren. I've left the DVD as it was in spectrometer v2.0 (test: https://spectralworkbench.org/spectrums/91439) and it works. No..." | Read more » over 7 years ago
stoft "The angle is a function of (mathematical) of the detectable wavelength range and the diffraction grating (DVD) line spacing. My calculations and my..." | Read more » over 7 years ago
warren "@stoft or @cfastie may be able to provide more info, but I believe it's been shown that the exact angle is not as important within the likely resol..." | Read more » over 7 years ago
pablo "Thaks, Jeff. I'll try to use a wooden block with a hole in it, or made with pieces to allow the cable to pass. I'll keep distance and height from t..." | Read more » over 7 years ago
warren "Hi, sorry, we linked it to another page -- should perhaps make it more prominent; there's a link leading to the new location here: https://publicl..." | Read more » over 7 years ago
warren "Hi, Pablo - I think you can leave the DVD as it is, and the challenge will be to get it to remain in the same orientation with regard to the slit, ..." | Read more » over 7 years ago
dcchallener "Where is the video to assemble the box? " | Read more » over 7 years ago
stoft "@stef, thanks for the curve data. While the data is useful for comparison with relative sensitivity curves of other cameras, the data, unfortunatel..." | Read more » over 7 years ago
warren "Hi, this looks very cool - what is the app you're using? " | Read more » over 7 years ago
stef " khufkens-pi-camera-response-curves-3342e29_-3-.zip @warren,@stoft This may provide additional info. Stef " | Read more » over 7 years ago
warren "Hi, Abdul - could you link to the PDF design files for the box entry in the Materials list? https://github.com/publiclab/spectrometer3 Thanks! " | Read more » over 7 years ago
stef "@warren Thanks for your comments. Prior to the IR filter removal, I had no indication that there was a light transmission through the cover proble..." | Read more » over 7 years ago
stef "Done! " | Read more » over 7 years ago
stoft "What I've read is that the RPi camera used to use the OV5647 camera chip but has "upgraded" (changed chips) to a Sony IMX 219 PQ CMOS image sensor ..." | Read more » over 7 years ago
warren "Just wanted also to link to @stoft's input on this question in this comment: As to the RPi camera, it seems to have two "difficulties" which need ..." | Read more » over 7 years ago
warren "Great, thanks -- and just to link to the question I'd asked about this earlier: https://publiclab.org/questions/warren/09-28-2016/upgrade-a-diy-spe..." | Read more » over 7 years ago
stoft "Jeff, I inserted the component details in the note above, just before the plots. As to the RPi camera, it seems to have two "difficulties" which n..." | Read more » over 7 years ago
warren "Also -- just reading this through carefully, and was wondering if the line: I used the pick on the back of the lens ...could be clarified -- you..." | Read more » over 7 years ago
warren "Also - do you have links to scans done with and without this light cover, in bright conditions, to show folks the advantage of additional light dam..." | Read more » over 7 years ago
warren "Great build photos - I've added the upgrade:dssk tag to indicate to people that this is an upgrade that can work on the desktop spectrometer, and t..." | Read more » over 7 years ago