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 | ||
|---|---|---|---|---|---|
| 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 » | almost 7 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 » | almost 7 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 » | almost 7 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 » | almost 7 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 » | almost 7 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 » | almost 7 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 » | about 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 | |||
| gretchengehrke | "Hi @Mempet, Could you use a turbidity tube like this one: https://www.carolina.com/environmental-science-water-quality/carolina-turbidity-tube-120-..." | Read more » | about 7 years ago | |||
| gretchengehrke | "@donblair, I was just reading this again, and am again impressed by your elegantly simple approach -- such a great idea! It seems like this alterna..." | Read more » | over 7 years ago | |||
| gretchengehrke | "@bhikman, that integrated optical filter is neat, and surprisingly inexpensive! If you do pick this back up, I am super interested in seeing how we..." | Read more » | over 7 years ago | |||
| bhickman | "Hi @gretchengehrke. I kinda let this project fall though the cracks. I did have the sensor working pretty well, the only issue was interference fro..." | Read more » | over 7 years ago | |||
| gretchengehrke | "Hi @bhickman and @ggallant! I was just reading this research note and comments again, and it sounds like such a promising project. Are there any up..." | Read more » | over 7 years ago | |||
| gretchengehrke | "That's so great, Shan! " | Read more » | over 7 years ago | |||
| shanlter | ""Did the Chinese government state the methods they would use to evaluate each of these parameters?" yes, they state the standard methods. "Also, di..." | Read more » | over 7 years ago | |||
| shanlter | "Hi @gretchengehrke, sorry for responding late, I was in a temple with no internet access in the passing week. Yes, I've seen that page and I though..." | Read more » | over 7 years ago | |||
| gretchengehrke | "@shanlter, this is great! Have you seen the spreadsheet on the www.publiclab.org/wiki/water-sensors page? There are some other options there listed..." | Read more » | over 7 years ago | |||
| warren | "Hi, Gretchen - do you have some examples of when and where this technique has been successfully used by folks? Thanks! " | Read more » | over 7 years ago | |||
| jesseslone | "@donblair I noticed you have a more recent post about turbidity, I was wondering if you would choose a different light sensor than the Adafruit one..." | Read more » | about 8 years ago | |||
| eustatic | "NOAA and Coast Guard made this guide "Job Aid" to observing oil slicks from the air. It's state of the art for government. OWJA 2012 Here's some ..." | Read more » | about 8 years ago | |||
| gretchengehrke | "@tonyc, @mathew, @warren, @stevie, @donblair: I think an additional stretch goal that would be worthwhile is to be able to control the trap cam wit..." | Read more » | over 8 years ago | |||
| bhickman | "Hi ggallant. Your design files look great! I'm going to have to look into openscad. As far as a server, I don't think publiclab has one. I think mo..." | Read more » | over 8 years ago | |||
| ggallant | "I parked the openscad design files at https://www.dropbox.com/sh/mzp8gketcuqufkq/AADkG_kmo2xcL3iWYOLi4YCxa?dl=0 If there is a better place, such a..." | Read more » | over 8 years ago | |||
| bhickman | "Hi ggallant. I'm definitely interested in what you have put together. I'll check out openscad to see what you have. As for the pipe and air bubble..." | Read more » | over 8 years ago |