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
idev247 "Interesting. Thanks @cfastie and @warren. The answers seem to agree that the spectrometer might indeed be the right type of tool to measure color o..." | Read more » over 7 years ago
idev247 "I haven't bought a lux meter yet but what you mentioned is interesting. I could use the lux amount as a variable when doing the spectrometer measur..." | Read more » over 7 years ago
warren "Ah, Chris reminds me of an additional way to control camera gain control -- use a camera, like the Raspberry Pi camera, where you can more tightly ..." | Read more » over 7 years ago
cfastie "Wow, the Phillips Hue is a 15 dollar LED light bulb with a wifi module. It requires a proprietary wifi router (~$40). The free app can control up t..." | Read more » over 7 years ago
warren "Oh, interesting -- curious about your lux meter --- cost or link to buy one? You could use it perhaps to confirm that you're reading equal amounts ..." | Read more » over 7 years ago
idev247 "The divider is definitely an interesting idea. I've been looking around and maybe I could use two tools: A lux meter for brightness, and the spectr..." | Read more » over 7 years ago
idev247 "I'll still researching. Based on what I found I'm probably better off getting a lux meter for brightness, and maybe the spectrometer for color spec..." | Read more » over 7 years ago
warren "Hi, I think the spectrum comparisons would be relatively straightforward -- but keep in mind that the kit requires a calibrated reference light to ..." | Read more » over 7 years ago
madeinussr "@madeinussr awards a barnstar to xose for their awesome contribution! " | Read more » over 7 years ago
cfastie "Many plant species have leaves with broadly similar spectral reflection properties. So depending on the species it might be a challenge to distingu..." | Read more » over 7 years ago
warren "I don't know if it's helpful, but the folks in the #webvalley project used an exposure-controlled version of the DIY spectrometry kit to compare ra..." | Read more » over 7 years ago
rohanpaleja27 "Thank you, we would also like to take it to applications where we would differentiate between two green plants. Would a spectrometer be able to do ..." | Read more » over 7 years ago
cfastie "Depending on your goal, a spectrometer might not be needed to locate dandelion flowers. They are dramatically distinct from green leaves in the vis..." | Read more » over 7 years ago
xose "Impressive work warren!! Thanks!! " | Read more » over 7 years ago
warren "very cool! Also see the newer prototype I did a while back -- high hopes for it to be a bit more robust: https://publiclab.org/wiki/foldable-spec#U..." | Read more » over 7 years ago
warren "That's so cool! Thanks, please do -- " | Read more » over 7 years ago
xose "Hi there I've adapted the ink+hole upgrade to the foldable specrtrometer and think works pretty well. Ill post an upgrade with some test pictures o..." | Read more » over 7 years ago
stoft "There's still some clipping (source light intensity too high) so a comparison, using a cardboard mask (with a small hole in it), between the two bu..." | Read more » over 7 years ago
warren "Oh, interesting -- what types of bulbs were they? " | Read more » over 7 years ago
pablo "I've changed the bulb and used a less powerful one and I got good results: https://spectralworkbench.org/spectrums/91741 without the blue noise. W..." | Read more » over 7 years ago
pablo "Hi! I've followed all the recommendations (except refocus) but the blue hump is still there: https://publiclab.org/notes/pablo/11-09-2016/how-to-do..." | Read more » over 7 years ago
warren "Great idea to constrain and track this down -- it might make a good new question in its own right, esp. if it's a common issue (which seems likely)..." | Read more » over 7 years ago
stoft "No I don't think it is just inherent in the camera. The blue led has a fairly narrow spectrum (say 25nm at most) so producing a 150nm 'spread' woul..." | Read more » over 7 years ago
warren "OK - i guess the blue bulge is just a limitation of the camera... i had forgotten exactly. But if you subtract a baseline reading from any readings..." | Read more » over 7 years ago