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 | "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'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 | |||
| Ag8n | "I've seen a bunch of different things used, but cuvette s are most common. " | 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 | |||
| warren | "Oh, interesting! Maybe @programmer1200 would be interested in this, re: related work on a turbidity sensor... " | Read more » | almost 7 years ago | |||
| Ag8n | "The current epa method for turbidity, with standard prep, is at: Https://epa.gov/sites/production/files//2015-08/documents/method_180-1_1993.pdf ..." | Read more » | almost 7 years ago | |||
| liz | "I have heard that in China the turbidity standards in rural areas permit up to 3x more turbidity than in cities -- is this correct, and is there a ..." | Read more » | almost 7 years ago | |||
| warren | "@gilbert has compiled some more information on this over here: https://publiclab.org/notes/gilbert/09-22-2017/turbidity-mesurement-methods-regulati..." | Read more » | almost 7 years ago | |||
| warren | "If you have links to regulations or explanations of how they work, please chime in! " | Read more » | almost 7 years ago | |||
| warren | "@gilbert posted some resources on turbidity regulations (although it focuses more on methods to measure turbidity) on this page: https://publiclab..." | Read more » | almost 7 years ago | |||
| Ag8n | "Absolutely correct. The fluorescence spectrometer is the same layout as for the basic turbidimeter. The standards are a bit of a pain, but quite ..." | Read more » | almost 7 years ago | |||
| warren | "So a design using the Lego Spectrometer, for example, might need a right-angle light source -- but that's not so bad, since already with fluorescen..." | Read more » | almost 7 years ago | |||
| warren | "Hm, good point -- actually going back to an old post there's some great stuff here: https://publiclab.org/notes/donblair/08-25-2015/turbidity-001 ..." | Read more » | almost 7 years ago | |||
| Ag8n | "By definition, turbidity measures the amount of light scattered at a 90 angle. So there would have to be a change in the optical layout from the ..." | Read more » | almost 7 years ago | |||
| warren | "There are also a number of resources on turbidity monitoring -- DIY and otherwise, here: https://publiclab.org/wiki/turbidity " | Read more » | almost 7 years ago | |||
| warren | "There's also this post by @shanlter which could be helpful? https://publiclab.org/notes/shanlter/12-17-2015/waterfilter-kits-for-rural-chinese I ..." | Read more » | almost 7 years ago | |||
| Mempet | "Hi @gretchengehrke! Thanks for letting me know about this! I might actually be able to use it. However, one complication I have is the amount of li..." | Read more » | about 7 years ago |