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 | ||
|---|---|---|---|---|---|
| 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 » | over 4 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 » | over 4 years ago | |||
| warren | "If you have links to regulations or explanations of how they work, please chime in! " | Read more » | over 4 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 » | over 4 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 » | over 4 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 » | over 4 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 » | over 4 years ago | |||
| Ag8n | "Very interesting article. Thank you for posting it. Could you give more details on the turbidimeter you have developed? Regards " | Read more » | over 4 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 » | over 4 years ago | |||
| warren | "It would also be really cool to see a design adapted for the Lego Spectrometer! https://publiclab.org/wiki/lego-spectrometer " | Read more » | over 4 years ago | |||
| warren | "Related: How can we detect contaminants in water samples with a DIY spectrometer using reagents? https://publiclab.org/notes/warren/12-18-2017/ca..." | Read more » | over 4 years ago | |||
| MadTinker | "I would add the following: alkalinity, hardness, and perhaps ORP " | Read more » | over 4 years ago | |||
| warren | "There are also a number of resources on turbidity monitoring -- DIY and otherwise, here: https://publiclab.org/wiki/turbidity " | Read more » | over 4 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 » | over 4 years ago | |||
| warren | "OK, my next thought on this would be to scan 2 at once instead of 3, so that at least any non-evenness would be symmetric horizontally. But I'm not..." | Read more » | over 4 years ago | |||
| warren | "We had an old idea for this a ways back -- posted below. But yours connects so beautifully to the spectrometer, it's a great improvement! " | Read more » | over 4 years ago | |||
| warren | "This can be a helpful way to get the same exposure for two samples at once, which can be important when using a less-controlled camera like a webca..." | Read more » | over 4 years ago | |||
| warren | "Here's one attempt from a few years ago: https://publiclab.org/notes/cfastie/02-25-2014/mobile-cuvette-holder This was designed for a laser, but c..." | Read more » | over 4 years ago | |||
| programmer1200 | "Yes it is possible to redesign it for two cuvette at one time would just need to widen the area toward the spectrometer and double the area on the ..." | Read more » | over 4 years ago | |||
| warren | "Hi, @programmer1200 -- saw your post on a cuvette holder and wondered if it would be possible to use it for two cuvettes simultaneously? Perhaps by..." | Read more » | over 4 years ago | |||
| programmer1200 | "Hi Warren I'm also working on a beers law based machine for testing one cuvette at a time and measuring the amount of light penetrating through the..." | Read more » | over 4 years ago | |||
| warren | "I think the light is not evenly distributed, and in the scan I took, there's just more light in the middle. I'd like to correct for this but it's e..." | Read more » | over 4 years ago | |||
| donblair | "Hi @gretchengehrke! Sorry for the much-delayed reply :) and thanks for the comment. I, too, liked this approach -- basically, using the differenc..." | Read more » | over 4 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 » | almost 5 years ago |