Assess Turbidity in Water
turbidity

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