Desktop Spectrometry Kit
dsk

New version available This version of the kit is no longer in production, and have been replaced with the Desktop Spectrometry Kit v3.0. Order one from our store » **** ##Getting Started The 1-page instruction sheet which shipped with your spectrometer remains the best documentation to date on how to assemble it. There are now **two versions** of these instructions, as the kit was updated in late 2013. Please check that the type of camera matches the kit you have. The **flat, gum-stick-shaped circuit board cameras** are the newer ones (version 2.5 of the kit) and the **small grey box webcams** are the older 2.0 version: JDEPC-OV04 "gum stick" 3.0 version (see notice above for new instructions page) SANM "gum stick" 2.5 version: desktop-kit-instructions-2.5.pdf (140 kB) SYBA "grey box" 2.0 version: desktop-kit-instructions-0.4.pdf (200 kB) Here are the v2.5 instructions: ###Using your spectrometer Once you've assembled your spectrometer and are ready to use it, plug it in and visit [SpectralWorkbench.org](https://spectralworkbench.org) to begin recording data with it. The web-based software works in the **Chrome, Firefox and Opera browsers** on most computers and Android phones. ###(Peer) Support Public Lab is not a corporation; we're an open community of DIY environmental science researchers which you have just joined! The best place to get help is the spectrometry mailing list; to join, sign up in the form to the left. The spectrometry mailing list is made up of people like you, who are building and improving open source spectrometry techniques. Ask questions, look for help, and consider helping others too! You can also post a question on this site; it helps to share some photos or screenshots of what you're trying to do: [question:spectrometry] ###Resources * [Common hardware issues](/wiki/spectral-workbench-help#hardware-troubleshooting) * [Using the software](/wiki/spectral-workbench-usage) (including setup and software troubleshooting) * [Frequently asked questions](/wiki/spectrometer-faq) * [Background about the project](/tool/spectrometer) * peer-contributed [research on open source spectrometry](/notes/spectrometer) ###Design files: Insert for cutting out of stiff matte black card paper: https://publiclab.org/sites/default/files/desktop-spec-insert-1.1.pdf ###Upgrades A list of documented upgrades to the kit, if you're looking to further refine your device! * upgrade to the new version 3 spectrometer with [the upgrade kit](http://store.publiclab.org/collections/spectrometry/products/dsk-3-0-upgrade) * using an [acetate collimation slit](/notes/mathew/09-25-2013/photo-printed-collimation-slit-for-the-backpack-spectrometer) (as [available in the PL store](http://store.publiclab.org/collections/spectrometry/products/acetate-collimation-slits) -- basically a more precise, narrower slit, printed on plastic film -- for a more precise, though less light-sensitive, device (This needs better documentation on how to integrate it with the Desktop kit!) * darken the inside of the spectrometer box with black, matte, absorbent paint or felt * use a more light-sensitive camera ##Assembly photos These photos document the older, "grey box" version of the kit. If you have photos of the more recent version, please post them! Here are some photos of the build process to help you figure it out. It doesn't hit on every step but just the important parts -- **refer to the above PDF guide for a step-by-step guide**. Crease and fold up your black card insert. This will reduce reflection in the interior of your device. Keep the ink on the "outside" as it is reflective. Using a piece of double-sided foam tape, form a box with the tabs on the outside, keeping the longer tab on the bottom, as shown above. Press the foam tape firmly onto the bottom of the spectrometer case, with the long tab on top, as shown. Keep the imaging slit pressed up against the inside of the box's hole. ###Snap off the useless half of the webcam### Some cameras may rest flat on the side of the box; our kit includes a nice, compact camera with flat sides (hard to find! too much ergonomics!) but to make it fit you have to snap it in half. Don't worry, the non-camera half is empty! (If you're building this without a kit and can't find a flat-bottomed camera, you can use hot glue, epoxy, moldable plastic, or metal brackets to ensure that your camera stays level and rigidly in place.) ###Unscrew the lens and remove the infrared filter### Heating the lens a bit with a hair dryer, or by leaving it close under halogen desk lamp can help loosen it. The filter will look iridescent -- pry it out with a knife or sharp screwdriver, and throw it away. Screw the lens back in close to how it was. More tips on removing filters from other types of webcams can be found here: [Webcam filter removal](/wiki/webcam-filter-removal) ###Look at a barcode through the webcam to refocus it to about 22 cm (9") away### Be aware: the printed instructions incorrectly indicated only 5" away. You must focus 9" away to have in-focus spectra. Use a webcam program like Photo Booth or even https://spectralworkbench.org/capture (experimental). A barcode has fine details so it's a nice test of focus. (The above image is of an older kit) Rotate the camera lens to adjust the focus. You may need to *gently* use a pair of needle-nosed pliers at first. Anything around 9 inches away (22cm) from the lens should be in focus. This means your slit will be in focus when the box is closed. If you don't carefully refocus your camera, your spectra will be of very low resolution. Now snap your webcam back together. ###Split the DVD-R into layers and cut a small rectangle from the clear layer ### You should be able to easily pry apart the DVD layers, and they're far easier to cut once they are separated. You'll need about a 1cm x 1cm square of the 'outside' edge of the disc. Don't get fingerprints on the DVD, and cut your "grating" from the outside edge where the track lines are more parallel. You can cut this piece down more precisely later. See also: Preparing a DVD-R to act as a diffraction grating for more information on removal of the residual aluminium and dye layers. Use two thin strips of double-sided tape to adhere the DVD fragment to the front of your camera. Use double-sided tape on the top of the webcam. If you're worried about the lens cover closing, you can use the tape to hold it open. Using the provided 45 degree angle guide, place the webcam -- facing outward -- on the side of the box as shown. You should first plug in the USB cable to be sure it will fit when the webcam is in position. Press it firmly down to adhere the foam tape to the side of the box. Now you can fold down the long black tab, close the 2 side tabs over it, and close your spectrometer, screwing it firmly shut. A zip tie or strip of tape can keep the USB cable from tugging on the camera and messing up your data. 8247399028_8b24a3d14f_c.jpg ###Suggested edits Better showing of discarding of opaque DVD piece: [![2014-06-07_08.21.43.jpg](https://i.publiclab.org/system/images/photos/000/004/547/medium/2014-06-07_08.21.43.jpg)](https://i.publiclab.org/system/images/photos/000/004/547/original/2014-06-07_08.21.43.jpg) ...


Author Comment Last activity Moderation
mathew "Thats a good idea. I was thinking of making a version of the paper grating support that had a protractor-like series of angles so someone could fo..." | Read more » over 9 years ago
cfastie "Mat, That's a pretty nice spectrum. Are you going to try adjusting the grating angle by 5° or so in either direction? I'm not sure it would make an..." | Read more » over 9 years ago
mathew "@spectraljugad The distances and angles come from @cfastie's empirical tests linked above in "relationship between grating, slit, and camera" for s..." | Read more » over 9 years ago
spectraljugad "Hi Mathew, Nice work and than you for posting detailed steps. I have two questions: Why is DVD diffraction grating pasted at 60° angle? How do ..." | Read more » over 9 years ago
amysoyka "This looks great! I am really impressed with the resolution of your spectra On the USB cable. My spectrometer broke when the pins came out of th..." | Read more » over 9 years ago
hank "Bravo! usb cable There are the little plastic crimp-on things made to protect electrical wire going through holes in metal boxes. Those come in b..." | Read more » over 9 years ago
cfastie "Good point. Here is a version with 4 shells and no support. RTegelbeckersDSK4s.x3g " | Read more » about 10 years ago
RTegelbeckers "At least the bolt holes for securing the lid and the holes for the cable clamp need tapping, so more shells would be recommended. On my own printer..." | Read more » about 10 years ago
cfastie "This is a nice design, well thought out. Here is an x3g file for printing it on a MakerBot Replicator 1 with these settings: PLA, right extruder,..." | Read more » about 10 years ago
Varquynne "How's the band separation on this spectrum for a CFL? (https://spectralworkbench.org/analyze/spectrum/20875) I've adjusted the focus of the webcam..." | Read more » about 10 years ago
geococo "Interested in rocks? I'm a geologist based in Australia, I'm currently trying to workout the best way to use this equipment for reflective spectrom..." | Read more » about 10 years ago
warren "Can you post links to some of your spectra demonstrating this? I think it might be best to just post a research note with some photos of your setup..." | Read more » about 10 years ago
dckim11 "Finally, I got some interesting data.....BUT the results confuse me. I am looking at algae in a petri dish placed between the light source and the..." | Read more » about 10 years ago
hank "You put the camera as far away from the slit as possible, instead of in the middle of the box -- is that an improvement? " | Read more » over 10 years ago
warren "Hi - it doesn't seem like it's lined up with the light bulb; but you could try to diffuse the light by placing a piece of semi-transparent (milky) ..." | Read more » over 10 years ago
dckim "Hello Warren! I have attached a screenshot of the "Configure" panel in the Capture interface using four different light intensities (at the very t..." | Read more » over 10 years ago
warren "Hi, Dckim - I just got your email. Can you upload a screenshot of the "Configure" panel in the Capture interface? I think you may need to adjust wh..." | Read more » over 10 years ago
mathew "Just linking these together. Here is Ligon's previous post " | Read more » over 10 years ago
Ligon "I seem to have two accounts, "Ligon" and "Naljorpa." I posted this inadvertently as Naljorpa. " | Read more » over 10 years ago
azaelbg "Hi dckim. One may get sharper and bright images by reducing the slit width (by cutting a narrower slit in a new black card) but then you loose brig..." | Read more » over 10 years ago
warren "Yes, you can download in the left-hand column on the spectrum page, it's a small grey bar with XML,JSON, CSV download links. So you think your bri..." | Read more » over 10 years ago
dckim "I attached the picture of the slit. It's from the "standard" desktop spectrophotometer kit that was purchased from here. Any tips with regard to ..." | Read more » over 10 years ago
Charles_Hamilton "Can you post a link to the specs or source for the webcam you're using above? Thanks. " | Read more » almost 11 years ago
sonofaquark "Awesome! I just ordered my kit and feel like a kid waiting for Santa. I was resigned to buying an Ocean Optics unit for 50x the price when this one..." | Read more » about 11 years ago