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 | ||
|---|---|---|---|---|---|
| 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 » | almost 5 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 » | almost 5 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 » | almost 5 years ago | |||
| emawatson12 | "I apapricate your content Ema Watson " | Read more » | almost 5 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 » | almost 5 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 » | about 5 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 » | about 5 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 » | about 5 years ago | |||
| mimiss | "When discussing ways to make the blinking light easier to read/a bit more accessible at last night’s event we flirted with the idea of 3 LEDs that ..." | Read more » | about 5 years ago | |||
| warren | "Maybe we could do both sound and light? That way it is adaptable for different abilities too. I don't know if we could have one port drive a light..." | Read more » | about 5 years ago | |||
| mimiss | "Please add any other things you can remember @charlotte_clark and @rollinrenola! " | Read more » | about 5 years ago | |||
| mimiss | "Love this build and excited to work more with these sensors. Thanks for putting together such great instructions. I had a chance to work with one ..." | Read more » | about 5 years ago | |||
| warren | "So, i realized entering control-shift-; in a google spreadsheet enters the exact time/date in a cell. Maybe we can modify the Arduino code to send ..." | Read more » | about 5 years ago | |||
| charlotte_clarke | "Yeah my comment came out odd due to markdown -- the underscore is present in both the Arduino code and the script. I was wondering whether it was ..." | Read more » | about 5 years ago | |||
| wmacfarl | "The script will miss substitutions if the data is coming in too quickly -- I put a bunch of delays in the code to slow it down to a point where it..." | Read more » | about 5 years ago | |||
| warren | "That is really odd. I tried a couple other things but can't figure out why this is happening. In theory it should just be pressing the tab key betw..." | Read more » | about 5 years ago | |||
| warren | "Hmm, the script is: function onEdit(e) { var val = e.range.getValue().toString(); if (val.indexOf('_now') !== -1) { e.range.setValue(Dat..." | Read more » | about 5 years ago | |||
| warren | "Oh, it looks like the sensor is sending "_now" instead of "now"... I wonder is it possible to modify the spreadsheet script to match that? " | Read more » | about 5 years ago | |||
| charlotte_clarke | "We have 4 turbidity sensors up and running thanks to Will's very clear and helpful instructions! Excited to use them for the event tonight. I do h..." | Read more » | about 5 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 » | about 5 years ago | |||
| warren | " " | Read more » | about 5 years ago | |||
| warren | "I did this! My first error it was a silly mistake - the yellow/red/black cable was plugged in backwards. "apparently" it makes a difference which ..." | Read more » | about 5 years ago | |||
| stevie | "Sounds great! @rockets just posted yesterday about the KnowFlow as well here: https://publiclab.org/notes/rockets/11-05-2019/knowflow-will-have-a-n..." | Read more » | about 5 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 » | about 5 years ago |