This page documents assembly and use of the Public Lab **Countertop Spectrometer** -- a pre-assembled, pre-calibrated spectrometer with a built-in dimmable light and stage, based on the [Desktop Spectrometry Kit](/wiki/dsk), which was offered as a reward during the [Public Lab DIY Spectrometry Kit Kickstarter](http://kickstarter.com/projects/jywarren/public-lab-diy-spectrometry-kit) Although designs and ideas have evolved since the Countertop Spectrometer was developed, it is still a robust way to measure absorption in liquid samples. ##Getting started ###Damaged parts Some of the countertop spectrometers experienced some damage during shipping, and if this happened to you, please contact **retail@publiclaboratory.org** to get replacement parts! Sorry! ###Setup Although the spectrometer is assembled when shipped, you need to attach the arm to the base (it is detached for shipping) and bolt on the sample stage. **Arm:** Plug the arm into the socket at the back of the base (not the light bulb socket!). Be careful not to pinch the USB cable -- you can tuck it into the arm tube or the base, and it will be pushed out of the way. Be careful not to tug on the cable -- you could unplug it from the interior of the spectrometer (it goes to a USB webcam). If this happens, you can keep disassembling the arm until you find where it unplugs and plug it back in. **Stage:** The stage is the piece of clear acrylic plastic in your box (it has a brown paper protective cover which you can peel off). Place the stage between the two black plastic clips on the spectrometer's arm. Using a screwdriver and your fingers, insert and tighten the bolts through both clips and the stage's matching holes. **Do NOT place the stage too low or the light may melt or burn it if left on high!** **Bulb & cables:** Screw your light bulb into the socket firmly. Plug in the spectrometer and turn on the dimmer by pressing it down. Plug the USB cable into your computer. ###Retrieving your calibration If you ordered this in the above-mentioned Kickstarter, your spectrometer was pre-calibrated at the "factory". To retrieve the calibration and begin taking calibrated data, follow these steps: * First, register on this site, and log into [SpectralWorkbench.org](https://spectralworkbench.org) with your new username. * Next, navigate to: https://spectralworkbench.org/lookup/ * Enter your calibration code, which is written on a round sticker on the bottom of your device. Calibrations can potentially drift over time, but re-calibrating yourself is easy. You'll need a fluorescent light bulb, which you can put into your light socket (turn the dimmer all the way up). Then [follow instructions here](/wiki/spectral-workbench-usage#calibration). ##More guidance and support For more on usage, troubleshooting, and support, check out these pages: * [Spectral Workbench](/wiki/spectral-workbench) * [Spectral Workbench Usage](/wiki/spectral-workbench-usage) ###Construction Here are some photos of the inside of the spectrometer to show how it's built. Be careful with the wiring! The wiring layout: [![IMG_0118.JPG](https://i.publiclab.org/system/images/photos/000/001/663/medium/IMG_0118.JPG)](https://i.publiclab.org/system/images/photos/000/001/663/original/IMG_0118.JPG) Roughly place the parts and align the holes: [![IMG_0117.JPG](https://i.publiclab.org/system/images/photos/000/001/665/medium/IMG_0117.JPG)](https://i.publiclab.org/system/images/photos/000/001/665/original/IMG_0117.JPG) Screw it together: [![IMG_0115.JPG](https://i.publiclab.org/system/images/photos/000/001/664/medium/IMG_0115.JPG)](https://i.publiclab.org/system/images/photos/000/001/664/original/IMG_0115.JPG) Finished! [![IMG_0114.JPG](https://i.publiclab.org/system/images/photos/000/001/661/medium/IMG_0114.JPG)](https://i.publiclab.org/system/images/photos/000/001/661/original/IMG_0114.JPG) Obviously we skipped some steps - one was cutting holes for all the parts and screwing the light socket around the hole cut in the outlet faceplate. But this shows most of the important bits.