As explained [in @donblair's primer](/notes/donblair/08-25-2015/turbidity-001), measuring turbidity means "measuring the amount of suspended solids in water -- solids that haven't fully dissolved". That is, "turbidity, an optical technique for assessing suspended solids in liquid -- is an important water quality parameter. Typically, light is shone into a liquid sample, and the amount of light scattered back out of the sample (off of particles suspended in it) is measured; the intensity of this scattered light is considered to be related to the amount of suspended solids in the sample." ([reference](/wiki/turbidity_sensing)) _image credit: https://castlebrookestreamstudy.weebly.com/_ This page needs help! * Info about regulations * Info about ecological or human health impacts * Advocacy leverage points * Constraints we're working within: cost, complexity, sensitivity, time There are a LOT of resources available on these pages by @donblair and others: * https://publiclab.org/notes/donblair/08-25-2015/turbidity-001 * https://publiclab.org/wiki/turbidity_sensing **** ## Questions [questions:turbidity] **** ## Sensors Here's a list of different turbidity sensors and measurement systems. See below for some Do-It-Yourself approaches to measuring turbidity, and [this page](https://publiclab.org/wiki/turbidity_sensing) for more information on how turbidity sensors works. * Kelley et al., An Affordable Open Source Turbidimeter http://www.mdpi.com/1424-8220/14/4/7142/pdf * Hackteria.org, Turbiduino: http://hackteria.org/wiki/DIY_turbidity_meters * Lambrou et al., A Nephelometric Turbidity System for Monitoring Residential Drinking Water Quality: http://www2.ucy.ac.cy/~faniseng/publications/SENSAPPEAL09.pdf - Fondriest review: http://www.fondriest.com/environmental-measurements/equipment/measuring-water-quality/turbidity-sensors-meters-and-methods/ - Hach overview: http://www.hach.com/asset-get.download-en.jsa?code=61798 (see [Water sensors](https://publiclab.org/wiki/water-sensors) for more, and [click here to add to this table](https://docs.google.com/spreadsheets/d/1UwjRqU8kHTwEcnDdO2Zxkr8zkFkaGfyePJ-cdnxJzw0/edit#gid=28737041)) **** ## Activities Activities for people to test methods (these develop over time) [activities:turbidity] **** ## Existing work [notes:turbidity] ...
| Author | Comment | Last activity | Moderation | ||
|---|---|---|---|---|---|
| MadTinker | "@cfastie Thanks Chris, I'd had forgotten this particular mod by Ed Mallon, and didn't notice the mods on your modules. I need to go back and review..." | Read more » | over 6 years ago | |||
| cfastie | "Ah, Arduino. Those DS3231 RTCs are designed to be used with a rechargeable coin cell (LIR2032) and they trickle current into the battery when curre..." | Read more » | over 6 years ago | |||
| MadTinker | "@warren Thanks. Perhaps, but if the info in the link is true, the solution is just finding a new RTC module that runs at 5V. I misread the power re..." | Read more » | over 6 years ago | |||
| warren | "Hmm! Maybe @cfastie could help with this issue? Very cool to see this in-progress! " | Read more » | over 6 years ago | |||
| nshapiro | "Oh those are great finds! I would think for $18 that is probably just as (if not more) affordable as making it one's self (including labor time). I..." | Read more » | over 6 years ago | |||
| Ag8n | "In the lab where both epa and fda testing was done, we always used the turbidity meter. We used color comparison tubes, too, just not for turbidit..." | Read more » | over 6 years ago | |||
| MadTinker | "DFRobot makes a Turbidity Sensor For Arduino (SKU:SEN0189). It's sitting in my forge right now and integrating it with a Mini-Pearl logger ( @cfast..." | Read more » | over 6 years ago | |||
| stevie | "I posted a question this morning about how to choose between different methods for monitoring turbidity. Does anyone on this thread have some insig..." | Read more » | over 6 years ago | |||
| stevie | "I've noticed there are a couple different methods for monitoring turbidity: Secchi disks: where users putting a disk into a body of water and mea..." | Read more » | over 6 years ago | |||
| stevie | "Here are neat instructions on constructing a turbidity tube by Elizabeth Myre & Ryan Shaw:: http://www.virginia.edu/blandy/blandy_web/education..." | Read more » | over 6 years ago | |||
| stevie | "Oh that decal is nice! I also found a couple really inexpensive secchi disks $18-$25 verses the Lamotte ones which are around $42-70. https://www..." | Read more » | over 6 years ago | |||
| nshapiro | "Very cool! i haven't but seems pretty straightforward just like the technique itself. If you have other uses for black and white rust resistant pai..." | Read more » | over 6 years ago | |||
| Ag8n | "Google " epa method 180.1 determination of turbidity... ". It's dated August of 1993. Should get you started. " | Read more » | over 6 years ago | |||
| Ag8n | "Google epa method 180.1 turbidity by nephlometry. It's dated augu " | Read more » | over 6 years ago | |||
| stevie | "Neat do you know where I could find some methods to do this written out? " | Read more » | over 6 years ago | |||
| programmer1200 | "I'm doing great, school (zoology was harder than I thought lol ) been keeping my busy but I have not forgotten my projects, still working on perfec..." | Read more » | over 6 years ago | |||
| Ag8n | "I've seen a bunch of different things used, but cuvette s are most common. " | Read more » | over 6 years ago | |||
| warren | "Hi, @programmer1200 -- how are you doing? Any updates about your project? Hope you're well! " | Read more » | over 6 years ago | |||
| warren | "Are cuvettes standard for turbidity? We actually stock them in the Kits store, so that'd be convenient. https://publiclab.org/spectrometry-sampling " | Read more » | over 6 years ago | |||
| Ag8n | "If you are looking for 1 cm x 1 cm cuvettes , they should be transparent on all four sides. This way, they can be used for both turbidimeters and ..." | Read more » | over 6 years ago | |||
| WaterGeek | "Great work and super useful for citizen's looking to track the quality and state of open water. We've been looking into something like this for dri..." | Read more » | over 6 years ago | |||
| Vendy | "Thanks to you man! " | Read more » | over 6 years ago | |||
| gretchengehrke | "@programmer1200, This is great! I agree with Chris and Holger that light scattering at a 90-degree angle is the standard approach for turbidity, an..." | Read more » | over 6 years ago | |||
| programmer1200 | "Totally understand where your coming from , its very possible im having some loss because of that, to account for the possible over bright light so..." | Read more » | over 6 years ago |