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
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 » over 11 years ago
cfastie "Gerhard, The exposure on that spectrum is almost perfect. There was a little too much light at 336 nm, and that peak is flattened a bit. The chann..." | Read more » over 11 years ago
Gerhard34 "Hi Chris, I'm trying to following your advice to avoid overexposure and wondering about the different exposure levels in my spectrum https://spectr..." | Read more » over 11 years ago
warren "I echo Chris's comments with two additions: we could perhaps improve the calibration by having the interface "snap" to the nearest peak when you ..." | Read more » almost 12 years ago
warren "What a fantastic writeup. It's really exciting to see all the matching CFL spectra being posted: https://spectralworkbench.org/tag/cfl " | Read more » almost 12 years ago
cfastie "Hi Jan, Thanks for this post. It is really good to see data on the effect of the blue LED. Your spectrograph makes it clear that most people will..." | Read more » almost 12 years ago
pluharj "Hi hi_cloud, thank you for your quick tip. I am thinking about breaking off the led diod. What do you do with your spectrometer? Any project or pla..." | Read more » almost 12 years ago
hi_cloud "Hi there, I coloured in the blue LED with a black marker, this seemed to solve the blue noise problem. " | Read more » almost 12 years ago
ckmurt "one final note, my camera is facing inward in the box which seems to give it better geometry with the slit on mine. " | Read more » almost 12 years ago
ckmurt "also it seems that there might be some problems with the calibration program. It often gives odd numbers for the wavelengths, at least for me. " | Read more » almost 12 years ago
ckmurt "I've been tweaking the setup today, its much crisper. I think some of the noise on the blue spectrum may have been from the blue light on the webca..." | Read more » almost 12 years ago
warren "The blue is not so bad... i think that blue peak may just be broader, see these examples: Is your bulb a "warm" fluorescent? There are mor..." | Read more » almost 12 years ago
ckmurt "So i refocused it, this was the most recent calibration, the red and green channels are producing very clear and crisp peaks and valleys, however, ..." | Read more » almost 12 years ago
ckmurt "Nice detective work, I'll give that a try today and see how it goes. " | Read more » almost 12 years ago
warren "Hi, ckmurt - i double checked by going through the build process from scratch again, and you're right -- 3-5" is too close. For whatever reason it ..." | Read more » almost 12 years ago
warren "Well, it's definitely in focus now, if that's 4". How are your spectra looking now? " | Read more » almost 12 years ago
ckmurt "I posted a photo of the barcode at 4". I have other distances at well, its focused from approx 3-5 in. You're welcome to use this on the wiki. " | Read more » almost 12 years ago
warren "If you have a chance to upload a photo of the barcode while it's out of the case, that can help us narrow down what's going on. Once we solve this..." | Read more » almost 12 years ago
ckmurt "I did the IR conversion, I tried to focus it on a barcode 3" away before I assembled the kit. I will try to redo it. Will upload the pic of the lam..." | Read more » almost 12 years ago
warren "Did you do the infrared conversion? In any case, I bet your camera is out of focus. You do need to focus it closer, whether or not you do the conv..." | Read more » almost 12 years ago
warren "Hi! I didn't realize it was a kit -- i thought you'd built it yourself from scratch. In this case the slit is probably correct since it's been lase..." | Read more » almost 12 years ago