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 | ||
|---|---|---|---|---|---|
| mcafeecloud | "This is very Amazing and Very Informative Artical we get a lot of information from this article we really appreciate your team work keep it up and ..." | Read more » | about 4 years ago | |||
| joyofsoy | "@mmbaustian did exactly this in Barataria Basin! Curious to know the answer from Hoon — Cyndhia R. (@CoastalRedwoods) February 5, 2020 " | Read more » | about 4 years ago | |||
| joyofsoy | "Perhaps if you collect both secchi and turbidity data frequently over a long time period at different sites and plot all the data, you could identi..." | Read more » | about 4 years ago | |||
| joyofsoy | "Maybe you could make a daily calibration curve?— Diana R. Di Leonardo (@SwirlingSands) February 5, 2020 " | Read more » | about 4 years ago | |||
| joyofsoy | "You could maybe make one for a specific site but I'd want to test it over a long time period before using it.— Diana R. Di Leonardo (@SwirlingSands..." | Read more » | about 4 years ago | |||
| joyofsoy | "And if you were to come up with a conversion factor, I imagine it would probably be very site and time specific, it wouldn’t be a value you could a..." | Read more » | about 4 years ago | |||
| joyofsoy | "We shared this question on our social media and received these responses From my understanding, secchi disks are a measure of light penetration de..." | Read more » | about 4 years ago | |||
| Tarek_Omar | "The digital sensor tell the turbidity by measuring how much of a known light intensity reaches its light sensor in a known amount of liquid and its..." | Read more » | about 4 years ago | |||
| nehagupta9994 | "We are providing social media account which helps to grow your business and you connect many peoples and increase your connection and followers. li..." | Read more » | over 4 years ago | |||
| emawatson12 | "I apapricate your content Ema Watson " | Read more » | over 4 years ago | |||
| wmacfarl | "This screw actually /doesn't/ calibrate the sensor. It sets the /threshold/ for digital output. I completely forgot about this when I wrote my re..." | Read more » | over 4 years ago | |||
| warren | "I think there is a little screw that can be turned to "tune" each sensor board, so I wonder if you could put both in the same sample and use a smal..." | Read more » | over 4 years ago | |||
| zengirl2 | "Hey, I have a couple of questions that may help to look at the hardware side: Did you use a phone cable for the USB or is it a legit cable used f..." | Read more » | over 4 years ago | |||
| webbhm | "@mimiss These sensors are cheap because they have limited accuracy, they were designed for dish-washers and the like, not technical analysis. Howe..." | Read more » | over 4 years ago | |||
| mimiss | "Please add any other things you can remember @charlotte_clark and @rollinrenola! " | Read more » | over 4 years ago | |||
| warren | "Folks at NASA AREN (#aren) sent this over -- a smartphone method for water color, interesting! http://misclab.umeoce.maine.edu/research/HydroColor..." | Read more » | over 4 years ago | |||
| bhickman | "Hi wmacfarl, Typically you would want to have some idea of the turbidity of whatever unknown sample you want to measure. If your measuring a fresh..." | Read more » | over 4 years ago | |||
| Markos | "Hi wmacfarl, Some more info. This type of sensor does not measure turbidity exactly. It measures the absorbance, or attenuation of light when pas..." | Read more » | over 4 years ago | |||
| Markos | "Hi wmacfarl , I've been thinking about affordable ways to calibrate diy photometric devices without having to use commercial standards like formaz..." | Read more » | over 4 years ago | |||
| warren | "Looks like there is an issue with reply by email, or possibly the list => email system, but Alan Marchiori responded on the plots-waterquality l..." | Read more » | over 4 years ago | |||
| Aleksi12358 | "What contaminants exactly you are talking about? There is photometer reagents for many different chemicals. For example this shop has many differen..." | Read more » | almost 6 years ago | |||
| warren | "Looks like @shantler, @anngneal and @donblair have written a bit about this! https://publiclab.org/notes/shanlter/07-03-2017/monitor-transparency-..." | Read more » | about 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 » | about 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 » | about 6 years ago |