Question: Is there a simple and reliable way to test the rigidity of the spectrometer?

bsugar is asking a question about spectrometer
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by bsugar | August 22, 2016 22:12 | #13388


What I want to do or know

What situations can I deploy the spectrometer in and how long can I use it under various conditions?

What should I expect when traveling with it? Suppose I put it in my bag in a cardboard box to protect it; should I place packing material around spec or will the box be enough?

Can I quickly move it from one place to another or does it require special handling even when I do nothing more than rearrange my setup on the table?

What happens to it if it gets wet? When (if) it dries will it retain it's former rigidity?

What if it gets accidentally crushed? Can I prop it back up again, or are the perfect 90 degree angles essential to its functioning?



5 Comments

Hello bsugar,

The DSK 3.0 is made of paper. The paper is, without getting technical, slightly more rigid and slightly thicker than a greeting card. But, that said, it is still paper. If it gets wet it will have ruined the electronic webcam inside. If it gets crushed, the same thing is likely to have happened.

For safe long distance transport, it would be best to disasseble the housing and reconstruct it once you arrive at your destination. The housing is only folded, so it can be disassembled and reassembled a few times. You could keep the bench, which is rigid, and holds a wood block with webcam and cable velcro-ed to a wooden platform, in a plastic bag inside of a box to keep it safe (box) and waterproof (bag).

Moving it across the desk is fine.

We would love to see builds that use rigid containment, and if a build using rigid containment gets developed at a reasonable price point and to a mature enough level to warrant testing I would be happy (as the Public Lab Kits Dept Coordinator) to do what I can to facilitate a beta test of it.


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@stoft has proposed a set of tests and thresholds for different rigidity"standards" of sorts, here: https://publiclab.org/notes/stoft/09-15-2016/what-mechanical-specs-can-and-should-plab-spectrometers-meet

They include things like types "3" stresses and a "drop test" from different heights.

I also think we might differentiate between desired rigidity when transported in its box (packaging) vs during use.

Update: we tried out this set of tests! Read more here: https://publiclab.org/notes/warren/10-17-2016/stress-testing-the-desktop-spectrometry-starter-kit

I also wanted to link back to this idea of monitoring the green peaks over a period of time:

As to how to measure this, I'd suggest a real-time display of say a green peak from a stable lamp where the display is a live 3-5 point running average of that peak's value, plotted not to show the absolute value, but the difference from the 'norm' so as to observe drift. The analogy is an oscilloscope. Then, handle the device and watch for correlations between the mechanical and the signal change -- which should be rock solid relative to the mechanical mounting of the optical components and the USB cable.


Updated my answer: yes!


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