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
warren "Also -- perhaps there could be a comparison of spectra with air gap vs. film gap... and to test your build, you might ask people to post a before/a..." | Read more » over 7 years ago
warren "I like this a lot! I'd try it out but I'm inclined (myself) to take things slowly -- I want to boost replications/builds on the other upgrades you'..." | Read more » over 7 years ago
warren "Also - I noticed you're using a compact fluorescent lamp as a light source - but are you measuring absorption? In that case you probably want a bro..." | Read more » over 7 years ago
cfastie "The sensors in consumer cameras have very low sensitivity at wavelengths shorter that 400 nm. Some cameras are slightly sensitive down to about 380..." | Read more » over 7 years ago
warren "Oh great; @khufkens also shared that on this site! https://publiclab.org/notes/khufkens/11-02-2015/ov5647-raspberry-pi-camera-spectral-response-qua..." | Read more » over 7 years ago
warren "I found that V4L2 driver apparently makes it possible to use the raspberry pi camera in Firefox with webrtc, the API Spectral Workbench uses: https..." | Read more » over 7 years ago
Siphirobe "I was wondering the same thing, just with the PiNoIR camera since I am more interested in remote sensing of vegetation. " | Read more » over 7 years ago
stoft "@warren, I didn't see you comment about a draft of test types for replication experiments so I just posted them at the end of this published note o..." | Read more » over 7 years ago
warren "Oops, the event is here: https://publiclab.org/notes/warren/09-27-2016/document-your-hardware-upgrades-at-parts-crafts-documentation-days-oct-12-19 " | Read more » over 7 years ago
warren "Hi Dave - I wanted to try out a set of tests when "reproducing and testing" the stability upgrade at the #documentation-days events on the 12th and..." | Read more » over 7 years ago
david_uwi "The display uses SPI communication (it has an internal ILI9341 driver). The PIC16F1788 has a hardware SPI module. These type of TFT displays can be..." | Read more » over 7 years ago
warren "Hi, this looks really cool! Are you interested in posting build instructions so others can follow your steps? I'm impressed at the cost -- what's ..." | Read more » over 7 years ago
david_uwi "Here's a real spectrum which I stored on the SD card. It is of potassium permanganate. Because there is a very strong absorbance 500-580 nm and the..." | Read more » over 7 years ago
david_uwi "It uses a TSL1402 diode array (I got mine from digikey) it has 256 pixels. A holgraphic diffraction grating (1000 lines) plastic lenses x2 (3 cm fo..." | Read more » over 7 years ago
stef "Very nice, but more detail is needed. stef " | Read more » over 7 years ago
stef "@warren After sleeping it over, realized that due to the no IR filter of the raspberry the bandwidth response will be different from the published..." | Read more » almost 8 years ago
stef "@warren Here is a link http://www.khufkens.com/projects/ov5647-spectral-response/ and here is a zip file khufkens-pi-camera-response-curves-3342e..." | Read more » almost 8 years ago
warren "That's a great thing to point out -- do you per chance have a link to the spectral bandwidth of the sensors? Thanks! " | Read more » almost 8 years ago
stef "Unfortunately I did not do a baseline measurement to do a comparison. Will keep that in mind for the future. stef " | Read more » almost 8 years ago
stef "The BIG advantage of the Raspberry Pi is the use of the Sony IMX298 sensor whose spectral bandwidth is known and is 16 megapixel sensor. Much like ..." | Read more » almost 8 years ago
warren "Thanks a lot! Have you seen a significant drop in baseline light after the painting? We hope to replicate this more at these upcoming events: http..." | Read more » almost 8 years ago
warren "Hi, this is excellent, thanks! Would you be willing to post it as a "replication" using the button above: Document your attempt to build this ? Tha..." | Read more » almost 8 years ago
stef "@warren This shows a metal 1/4-20 metal adapter for a tripod mount also addition of the rear 1.5X2 bulkhead with an indicator power on lead for t..." | Read more » almost 8 years ago
stoft "@warren, the black ink looks quite dark in the photo and seems easy to apply. Hope it cures well. I believe the primary factors are 1) the black c..." | Read more » almost 8 years ago