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# Question: What's the best setup for a copper rod or copper plate test for DIY hydrogen sulfide detection?

by warren |

At the #Barnraising, folks explored a few different ways of preparing copper sheets for a DIY hydrogen sulfide test (see #h2s-copper-pipe for more on this technique, where copper discolors in the presence of hydrogen sulfide, or H2S).

I saw some pretty interesting variations, aiming for

• ease of construction
• low cost
• ease of cleaning (you have to regularly scrub the copper surface with acetone)
• simplicity

What did folks come up with? Photos please!

I was really excited to work on this at BarnRaising. As a group we constructed sensors by using tin snips to cut sheets of copper, which is a bit tricky as the snips are sharp. Since I work with copper tape doing circuits, I experimented with using pieces on cardboard. Not only is it fun looking, but it makes a great project for families. My next step is to try using larger copper tape to create a leaf just a bit smaller than someone's hand. I may even scribe some lines for decoration after the sanding. Anyway, the tape still needs to be tested to see if it stands up to weather and if the thickness is okay for sensing. As for waterproofing, perhaps the tape could be applied to pieces of upcycled milk cartons or jugs. Then, the sensor could be placed in an upside-down plastic bottle. That way air can enter without the sensor getting wet. Kind of like a modern ship in a bottle. Here's two pics--one of the sensors we made hanging at Barnraising, and also a close-up of my prototype.

This is really cool. Thanks for sharing this, Leslie!

I was wondering if sheets could be nailed into a wooden plate.

It does seem like it would be ideal for the sheets to be flat, so we can more easily control lighting when photographing them -- that way things like glare, lighting direction, and angle can be more easily controlled.

Like the strips in this note, which are easy to compare due to their being flat and evenly lit:

https://publiclab.org/n/10576 and associated photo:

Just wanted to link over to this discussion of copper "badges": https://publiclab.org/questions/warren/12-06-2017/what-are-some-options-for-copper-materials-to-make-a-copper-plate-test-kit

I was looking for some pre-cut smaller pieces of copper in standard sizes, in part to avoid the warping that cutting big sheets with shears can cause. I found these copper stamping blanks that have 2 holes predrilled:

https://www.amazon.com/RMP-Stamping-Blanks-Rectangular-Copper/dp/B00MHWRLDI/

They're $13 for 10, so$1.30 each, and the holes could make it easier to mount them.

I tried scrubbing these with acetone after using very strong double-sided tape to attach them to a wood plank. So far it doesn't seem like the acetone is dissolving the adhesive!