Public Lab Research note

Oil testing kit Evaluation

by chongyukwai | October 04, 2015 11:32 04 Oct 11:32 | #12264 | #12264

What I want to do

The destop spectrometer kit and the oil testing kit was set up as below. The slit was using the standard slit provided in the kit



My attempt and results

The laser, the camera is working properly and the substance can produce certain color of fluroscene. However,No spectro data has been produced by this kit. There are several issue for this kit. Firstly there's a alignment problem between the laser and the currette. Therefore, the fluorescence light due to the blue laser was unable to produce. It is recommended that embedding the currette directly to the slit. Secondly, 90 degree fluorescence side light of the organic matter is too weak. It is recommended that forward light(Laser,detector and currette should form a straight line) should be detected instead of side light. Thirdly, spectrum was not produced even the light has been passed through to the camera(don't mention the camera, even the spectrum using naked eye cannot be seen). diffraction grating angle needed to be adjusted.

Questions and next steps

Conclusion: This kit cannot produce a significant result and need to be modified Update on 10/10/2015 Setting modified:


Technical problem:Camera cannot be anchored properly. Therefore, the diffraction grating is not completely on the view of the camera(which blocked some of the image) No spectrum has been produced at this stage even though I am directly spot on Desk Lamp! 20151010_233447.jpg


Laser,detector and currette should form a straight line

I think this setup would be a problem because the laser light is VASTLY more powerful than any fluorescence, and the camera sensor would probably be destroyed (just as an eye would!), or at least not sense anything besides the laser.

Looking at your photos, I think the laser alignment issue may be due to the OTK frame being mis-assembled; take a look at this image for reference:


See how your laser and slit are not set up the same way? The narrow slit pointing upwards in yours should be aligned so that the light passes through it on the way to the slit. Read more and look closely at the images here, especially in the comments:

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Also note that my spectrometer may be built backwards, but the image is still helpful.

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