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
stoft "With non steady-state sources, measurement error results from asynchronous data sampling. The 'fix' is either long integration time (assuming the s..." | Read more » over 5 years ago
jenjimah "Sure I'll post a question about it! After stewing on it a while, I don't think it should be a huge issue in most relevant contexts, (esp. for other..." | Read more » over 5 years ago
jenjimah "Thanks! It looks like khufkens predicted the response from >700 as the data was not yet available. If you look at the spectrum published by Sony..." | Read more » over 5 years ago
jenjimah " Great fodder for thinking about. 1) Agreed, having an individual light measurement per plant has advantages in certain scenarios. I guess it comes..." | Read more » over 5 years ago
MaggPi " This may be OBE but Hufkens has posted files of the PI response curves: https://khufkens.github.io/pi-camera-response-curves/ which were also r..." | Read more » over 5 years ago
stoft "Ok, the project concepts are taking shape which always prompts more thoughts. 1) By 2D mapping the light spectrum and relative intensity, you will..." | Read more » over 5 years ago
warren "Hi! I think the question of rolling shutter might deserve it's own question posted, to really dig into - it's a great question! One thought I had w..." | Read more » over 5 years ago
jenjimah "I was just reading on the pi website about the rolling shutter and I was wrong about the global shutter (it said only cameras with physical shutter..." | Read more » over 5 years ago
jenjimah "So I was reading about minimum exposure time of the Pi cameras and learned that it uses something called a "rolling shutter", which means it reads ..." | Read more » over 5 years ago
jenjimah " Yes that's exactly what I intend to do with the sun. Given sensor stability, and no shifts or changes in the spectrometer's build, calibration wou..." | Read more » over 5 years ago
stoft "A few more thoughts... On absolute 'average' intensity - You could use a Solux source (at fixed distance and known orientation) as a transfer stan..." | Read more » over 5 years ago
stoft " Ah, I've seen the curve on the web but it was not attributed to the specific sensor. It's helpful to now have that information. It looks like the ..." | Read more » over 5 years ago
jenjimah " Hi Dave, I just heard back from Sony regarding the IMX219 Sensor response. Here's the pdf and a screenshot: IMX219_Spectrum.pdf Although it doe..." | Read more » over 5 years ago
stoft " Jasmin, glad my previous notes were helpful. I did find one plot for the IMX219, but it was not from Sony and only covered to 700nm. The IMX265 c..." | Read more » over 5 years ago
jenjimah " Hi Dave, I looked at some of your posts before writing this one, actually! Your work is super helpful. I also couldn't find IR data from the Sony..." | Read more » over 5 years ago
stoft "Interesting project. I did not readily find spectral response curves from Sony on the IMX219 sensor though others in that family of devices appear..." | Read more » over 5 years ago
jenjimah "Hi Warren, thanks! I'll definitely try to document my process well as it comes along. I have a lot of motivation to get this going because I want t..." | Read more » over 5 years ago
warren " This is really cool! We'd love to see build photos as you go. We're also really interested in lighting setups and would love to see more documenta..." | Read more » over 5 years ago
mimiss "I did this! " | Read more » over 5 years ago
B-winters " If you are interested in getting access to the original CAD files, they are available for use on www.onshape.com under the file name "Visible Spec..." | Read more » over 5 years ago
B-winters " chunbr, thanks for you interest. I apologize for missing your comment and questions, I have been exploring some new adaptations to this system tha..." | Read more » over 5 years ago
JSummers " Hi Ag8n, Thanks for the comment. I am glad you are interested. We just connected the VBAT pin to the +3.3 volt bus. You did not miss any descrip..." | Read more » almost 6 years ago
Ag8n " With your vbat pin, did you connect it directly to the +3.3v or go thru a pull up resister? What value resister did you use? Very interesting pr..." | Read more » almost 6 years ago
chunbr " I did this! Use 25.103 as the multiplier to scale the .stl file to the proper size in Cura and also the diffraction gradings are available on Amaz..." | Read more » almost 6 years ago