The Public Lab Desktop Spectrometry Kit 3.0 is the latest version of the spectrometer. Read more about our Spectrometry program, the Oil Testing Kit it is is a part of, or the history of development. Previous versions 2 & 2.5 are here.

Parts List

• two-piece custom box and fold-up pieces printed on Neenah Sundance Eclipse Black Smooth 100 # paper. Download the latest print and cut files on github
• "gumstick" webcam (from a laptop screen) with USB cable. datasheet: Spec_of_JDEPC-OV04_Ver_1.01.pdf
• 45 degree wooden (pine or ash) block, 3cm x 3cm x 3cm
• Masonite bench 1/4" (6mm) x 40mm x 235mm
• 50cm of 3/4" (2cm) width adhesive-backed loop fastener (Velcro-style)
• 25cm of 3/4" (2cm) width adhesive-backed hook fastener (Velcro-style)
• DVD-R
• photo emulsion printed slit 0.2mm wide printed on .004" acetate. files on github
• 6 yard roll of 1/8" Thermoweb Supertape double sided tape. (3mm)
• printed assembly instructions (below)

Using your spectrometer

Once you've assembled your spectrometer and are ready to use it, plug it in and visit 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:

Ask a question about spectrometry or Sign up to answer questions on this topic

Resources

• Common hardware issues
• Using the software (including setup and software troubleshooting)

• Frequently asked questions

• Background about the project

• peer-contributed research on open source spectrometry

Assembly

We're going to assemble the box, the bench that goes inside, the block the camera sits on, the angle that holds the grating in front of the camera, and the card that holds the slit in place.

In this photo, the bench is pulled out of the box and aligned with the slit card as it would be inside the box.

Assemble the box

step-by step video:

For the purposes of this instructional I've highlighted the edges of the box.

Place the box with the printing facing down. Pre-crease all the creases.
crease the box top as well.

Fold the left side of the box to the right, and insert the hold tab in place.

Fold the right side to the left and lay the box top on top so its tabs line up with the slots in the box bottom. Make sure the small rectangular holes on the top and bottom line up. We will put the webcam cable through that hole later.

Insert the tabs together. The box top will not lay flat-- don't worry.

Pull the box top back to the right and fold the inner walls to the middle.

Hook the inner walls together.

Fold the outer walls up and over the inner walls. Use the two circular holes in the outer walls to position the inner walls while folding the outer wall over.

Flip the box upside down and make sure the tabs have all popped out of the bottom of the box. Walk your fingers along the inside of the box and make sure all the tabs are popped out of the bottom.

Assemble diffraction grating and angle

Pre-crease along all the folds.

Fold the bottom flap up and out of the way.

Fold the sides in.

fold the bottom flaps up so they are aligned and hold them in place with the hook fastener.

put a strip of double sided tape down on top of the bottom flaps.

fold the middle flap down over the bottom flaps and stick in place.

Splitting the DVD

try not to touch the surface of the DVD anywhere, hold pieces by their edges so as to avoid fingerprints. Slice a quarter of the DVD out.

using a fingernail or small blade, wedge the two layers of the DVD apart. disguard the aluminized side. If too much aluminum is on both sides, split another quarter of the DVD.

Slice a small rectangular piece out such that the rectangular edges are perpendicular to the edge of the DVD. This piece should be 1cm or so (half inch)wide.

Put some tape on the top of the angle and place the diffraction grating on top so it sticks down about 1 cm. Try to press it into the tape without getting fingerpints on the part over the hole in the angle. when its in place, then clip off the excess.

Put the collimation slit on the card

place the collimation slit on the card so it lines up with the two lines printed on either side of the hole in the card. tape down with double sided tape, but leave on the protective top of the tape.

Slide the card into the front of the box.

Assemble the bench, block and camera

take the loop fastener (the fuzzy side) and cover the bench. it should take two strips next to each other length-wise.

Put two strips of tape on the underside of the camera.

Stick the camera down to the middle of the block's angled side. so that the bottom edge of the camera is flush with the edge of the block.

Put two strips of velcro on the underside of the block.

Putting it together.

use the 200mm measurement on the side of the spectrometer box to place the camera lens 200mm way from the slit. Press the camera's block firmly into the hook & loop fastener. Place the diffraction grating angle in front as shown.

Put the webcam plug through the box hole in the back of the box, snake it up and plug it into the webcam. It only goes one way.

Slide the whole bench in back first so that it gets under the USB cable, and press to the bottom of the box. to get it out, press through the circular hole in the bottom of the box.

When closing the lid, the flaps may get stuck by the block the camera is mounted on. This tight fit assures no light will enter the box, work the flaps in around the sides of the camera block.

You're ready to do some spectrometry! Go calibrate your spectrometer on spectralworkbench.org

Design Notes

consult the following notes on development for the evolution of this design. @mathew (paper spectrometer 1)[/notes/mathew/11-07-2014/a-paper-spectrometer-design] @mathew (paper spectrometer 2)[/notes/mathew/12-06-2014/a-paper-spectrometer-design-pt-2]