Alternative chemical sensors, such as webcam spectroscope

rsevs3

I think almost all of the info you need to make one is here

http://www.asdlib.org/onlineArticles/elabware/Scheeline_Kelly_Spectrophotometer/index.html

rsevs3

Jackpot

http://publiclaboratory.org/wiki/video-spectrometer

Everything you need to make one including the spectrum for ammonia, nitrites and nitrates. Now how to apply it?

Either that or my sleep deprived brain is telling me lies

BullwinkleII

DuiNui

That is a nice find, but it raises a point I made earlier.
NO3 for example seems to have 2 peaks at around 625nm and 660nm.
The RGB output file ranges from around 465nm to 605nm, I don't see how this problem can be overcome without access to the lowest level raw data from the camera array.

But in the video he talks about being able to "see" stuff in the IR range.
I can't get my head around that one, maybe I'm missing something here.

rsevs3

In the video where he builds it he seems to miss a few steps as compared to the step by step instructions where he removes the IR filter. I will try and make one tonight and see what comes out of it.

Glad i did actually find something useful and didnt just imagine it. lol

SuperVeg

for relatively little money you can buy a CMOS sensor and development kit (if you so desire) from digikey etc.
This way you can easily have access to the raw image information...
aaaaaaaaaaaaand........go !

rsevs3

But i cant try and make one tonight if i have to wait

Will look into it though

rsevs3

This is my first attempt. Spectrum is from an incandescent torch.

Attachment:

photospectrometer.JPG [ 78.66 KiB | Viewed 853 times ]

You can see that there is a reflection somewhere. I used matte black cardboard and it is still happening. So im not too sure how to eliminate it. I dont even really know if it needs to be...

I cant find how to increase the resolution of the webcam either. I cant find how to do it in XP and no internet on my laptop is hampering my efforts to get it working on it. Hopefully it is a clearer image at higher resolution.

rsevs3

This is an image from a fluro tube.

Attachment:

photospectrometer2.JPG [ 30.74 KiB | Viewed 853 times ]

Interestingly, the image is a mirror image when i use the XP webcam preview compared to when i use google+ hangout. Blue was on the left hand side when i set it up.

SuperVeg

Nice work rsevs3 !

different pc apps seem to handle the webcam differently. Some even turn the image upside down. Generally you can change it though...

katonafull

Very Nice!

I was hoping that someone else made it up.
Which version spectroscope did you make?

I planned...
I will pop the UV filter from the webcamspectroscope camera. and i will use an UV light source

:wave:

I found an UV/Vis experimental protocol, in which nitrate is detected in water.
With UV light source, and a photodetector
But it's in hungarian language...and i can't translate it well... but i will try it...

katonafull

rsevs3 wrote:

This is an image from a fluro tube.

Interestingly, the image is a mirror image when i use the XP webcam preview compared to when i use google+ hangout. Blue was on the left hand side when i set it up.

Please try it with the software,

https://github.com/jywarren/spectral-wo ... all/master

Or with the other spectral analysis software...

http://pilath.fw.hu/setupok/setupspektro2012.rar

In that we can see the wavelenght... and we can buy UV LED....we maybe see the spectra of the UV.....

katonafull

And here is the solution for the NIR range-->

http://publiclaboratory.org/tool/near-infrared-camera

rsevs3

katonafull, i have been trying for the last 2 days to spectral-workshop to work. Only a few minutes ago did i even get it to load. I still cant get an image into it

I tried in both winblows and linux. linux has been the winner so far, i can get the UI to load. It doesnt help that my $4.79 webcam is about the only one not supported in linux. Most programs can show the video from it except cheese and spectral-workshop.

katonafull

it is interesting

I tried to run the spectral program from PLOTS webpage
http://publiclaboratory.org/wiki/video-spectrometer

but the program isn't want to run...

ie it runs, but shows nothing only gray screen...

What the problem at yu?

But the hungarian program is running...

for the first time it didn't want to work, but I install the direct-x, and
I got an error message, and the google told me that i have to install tne net-framework 4 language pack...and now it's working.

And i made the mistake, that i run the program, and after plug the webcam...the program rfozen...

Than i plug the webcam, and after that i run the program, and it's work...but only the hungarian program, the other isn't.

So please try that too

http://pilath.fw.hu/setupok/setupspektro2012.rar

Please Somebody who has a webcam try out the PLOTS spectral program..
Don't have to make a spectroscope, only should check the program...

It seems better, like the HUN...

https://github.com/jywarren/spectral-wo ... all/master

If it won't work, i will send an e-mail to the Plots staff

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