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Some Suggestions for Spectrometer v3.0 and Oil Testing Kit (OTK) Attachment

by ygzstc |

Last Updated on September 2nd, 2015

I just wanted to share some ideas and suggestions for improving the stability of the spectrometer v3.0 and oil testing kit attachment. I'll try to keep updating/modifying this list of items time to time.

1- DVD holder attached to wooden block

If you need/want to re-place the current DVD holder, velcro is too strong and may damage the holder’s bottom section. So, you can attach the DVD holder to the wooden block instead. An idea of this attachment is in Figure 1. Also this may help to achieve inter-device compatibility.

Picture2.jpg

Figure 1 - DVD holder attached to the wooden block (Dimensions are not correct – just to illustrate the idea)

2 - Separate top for spectrometer

Folding edges of top of the spec tends to be torn easily (especially the folding edge on the camera side) so using tape might be a good idea. In addition, separate top might be a simple idea to modify without disturbing the optical setup at the bottom part. (For the sketch see Figure 2.)

20150802_140747.jpg

Figure 2 - Sketch for a separate top for spectrometer v3.0

3- Stabilizing the USB cable

You can use tape to stabilize the USB cable of the webcam to the wooden block to prevent disturbing the camera position (Figure 3)

20150803_102839.jpg

Figure 3

4- Increasing the stability of the OTK attachment

Some folded parts of OTK can be fixed using double-sided tape (or with few drops of glue) to make it more sturdy (Figure 4)

Picture1.jpg

Figure 4

5- Connection between OTK and spectrometer

Stable connection between OTK attachment and spectrometer is necessary. Tape/velcro on the bottom and some attachment like in Figure 5 on top may be useful. This also helps reducing unwanted ambient light to leak inside.

20150803_114421.jpg

Figure 5

6- External Power Supply for Laser

An alternative way to set up the laser is to use few additional cables an external battery holder (Figure 6). Advantages of this kind of setup are: (i) you can change the batteries and operate the laser during measurements without touching/disturbing the OTK attachment; (ii) you can even use an ac/dc adapter (3V dc output) to eliminate low battery charge (i.e. low laser intensity); (iii) you can even power the laser (or any other light source you want to test) using USB port of your laptop/PC. But you have to keep in mind that USB provides 5V output NOT 3V; (iv) you can have a smaller OTK attachment.

20150831_112104.jpg

Figure 6

7- Alignment between Spectrometer Slit and Cuvette Holder of the OTK

In my case, alignment between the slit and OTK was off. So, I used double-sided tape to adjust the height of the spectrometer (Figure 7). This also helps to have a more stable connection between the spectrometer and OTK attachment.

alignment.jpg

Figure 7

8- Modifying OTK for Absorbance Spectroscopy Applications

Having another opening on the back side of the OTK attachment (see Figure 8) allows us to use this attachment for absorbance spectroscopy applications as well. (Details like size, shape etc. needs to be carefully calculated though!)

abs.jpg

Figure 8

NOTE-1: Also, please check Mathew's and Dave's profile pages to see their great upgrade suggestions and illustrations for spectrometer and OTK attachment.__


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2 Comments

Hi, Yagiz! Awesome. Can you share some dimensions of the DVD holding part so we could come up with a vector design to add to the repository? https://github.com/publiclab/spectrometer3/

How do you think the angles on that could be drawn out, and does it go between the block and the velcro?

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For the L-shaped part in figure 5, I'm curious to hear @stoft's input - I'd like to see some kind of more rigid connection between the piece that has the slit and holds the cuvette, and the slit on the front of the spectrometer:

IMG_20150730_152002.jpg

Maybe there's some way to index it with a notch or something, then lash it in place using some of the connections I prototyped as long as there's a firm and precise indexing point to tension this against:

connection


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