**Conductivity** is a measure of a solution's ability to conduct electricity, as measured in Siemens per meter (S/m). (lead image by @ddileona) This page is under development, please add background info: * Info about regulations * Info about ecological or human health impacts * Advocacy leverage points * Constraints we're working within: cost, complexity, sensitivity, time Also see resources on this page: https://publiclab.org/wiki/conductivity_sensing ## Questions [questions:conductivity] **** ## Sensors Here's a list of different conductivity sensors and measurement systems. Also see below for some Do-It-Yourself approaches to measuring conductivity, and [this page](https://publiclab.org/wiki/conductivity_sensing) for more information. * [the Coqui](/wiki/coqui) **** ## Activities Activities for people to test methods (these develop over time) [activities:conductivity] **** ## Existing work [notes:conductivity] ...
| Author | Comment | Last activity | Moderation | ||
|---|---|---|---|---|---|
| donblair | "Also: how hard would it be to rig up some sort of 'pen' that connects to a 555 and writes out a 'record' of the conductivity on some physical mediu..." | Read more » | over 10 years ago | |||
| donblair | "ZOMG that's brilliant. I'm going to try to bring the materials required to do a rough prototype of this to Plymouth -- but anyway shouldn't be hard..." | Read more » | over 10 years ago | |||
| mathew | "Yes, exactly! I would love to see an analog "retro edition" riffle with a microcassette recorder and a 555, maybe in a really nice Ball jar. " | Read more » | over 10 years ago | |||
| warren | "Wow, i'm not sure I follow all of this, but is one potential advantage of the 555 that we could even skip the arduino entirely, if, say, we wanted ..." | Read more » | over 10 years ago | |||
| donblair | "E.g. I just found this: http://wiki.openmusiclabs.com/wiki/PWMDAC And, oh gosh, this is fun: http://sensorium.github.io/Mozzi/ And: http://www.ucho..." | Read more » | over 10 years ago | |||
| donblair | "Good call on the power control chip -- for the riffle-ito design, I'm just using an LDO, which should provide a relatively clean signal? But yeah,..." | Read more » | over 10 years ago | |||
| mathew | "the power issues are going to be tough. Most power control chips do tricky high-speed things to push out a DC signal and the voltage isn't very cle..." | Read more » | over 10 years ago | |||
| donblair | "Egads! Mat, thanks for pointing this out! I totally flubbed that one: in the 555 approach, the signal that is passing through the water is indee..." | Read more » | over 10 years ago | |||
| mathew | "the 555 is pretty simple. There's not that much inside of it. If it simplifies the power circuitry issues you're facing then go with it. I hadn'..." | Read more » | over 10 years ago | |||
| donblair | "Ah -- great thoughts! And your comment points to an important issue, which is that I myself was unclear (and still am, a bit) as to the utility of..." | Read more » | over 10 years ago | |||
| mathew | "This is really cool. I would never want to discourage someone from using a 555. And it would be totally sweet to use audio gear to record and ima..." | Read more » | over 10 years ago | |||
| unmanaged | "I would be glad to send some SS welding rods to you free of charge... you have access to the scope and tools I do not... I planted the garden today..." | Read more » | over 10 years ago | |||
| bgamari | "Over the last few days I've been busily reworking some aspects of the measurement. Now we have a much lower excitation voltage (currently 100mV, al..." | Read more » | over 10 years ago | |||
| JSummers | "Hi Don, I agree with Cversek that you need to keep the voltage difference small. you also might want to look at using graphite electrodes. The ki..." | Read more » | over 10 years ago | |||
| donblair | "Cversek -- wow, thank you!!! What a useful collection of info. Your note convinced Ben to add a dual op-amp to buffer the conductivity output, and..." | Read more » | over 10 years ago | |||
| kanarinka | "nice work - it's great to see that the conductivity measurement is coming along like this! " | Read more » | over 10 years ago | |||
| cversek | "What is the max amplitude of the voltages you are applying across the screws? If this gets too high you could be electrolyzing the water, other io..." | Read more » | over 10 years ago | |||
| donblair | "Just noticed -- in that last plot, it looks like the 'falling times' (top curve) start 'slumping', whilie the 'rising times' (bottom curve) seem re..." | Read more » | over 10 years ago | |||
| EdMallon | "Hi everyone, Just a quick note to say the first gen loggers survived their initial 3 month deployment giving us real water flow data, (6m depth,~ ..." | Read more » | over 10 years ago | |||
| EdMallon | "Hi everyone. I just wanted to post an update as I have done some major code development for the Cave Pearl data logger recently, and a weeks wor..." | Read more » | over 10 years ago | |||
| EdMallon | "Hi Warren. Nice to meet you. Wrt cross posting, I am wondering about the content that would be most helpful to the audience here, as I interwove (w..." | Read more » | almost 11 years ago | |||
| warren | "Also see this newly posted discussion of dragging underwater loggers: http://publiclab.org/notes/maxliboiron/02-11-2014/underwater-plume-sampling-m..." | Read more » | almost 11 years ago | |||
| warren | "Wow, very cool, Ed. Would you be able to cross-post your blog here? How could we make that easier for you? I think a lot of folks here would be int..." | Read more » | almost 11 years ago | |||
| eustatic | "Ed, see my note, excited about this effort. http://publiclab.org/notes/eustatic/3-27-2012/thoughts-water-sensing-needs-non-profits-louisiana " | Read more » | almost 11 years ago |