Many people interested in measuring various **water quality parameters** that are relevant to environmental health in low-cost and accessible ways. Many have been working on low-cost, open-source sensors for water chemistry and physical properties, and there are also several commercially available water sensors and analog tools that can measure relevant water quality parameters. [![IMG_20171205_145207.jpg](https://publiclab.org/system/images/photos/000/022/802/large/IMG_20171205_145207.jpg)](https://publiclab.org/system/images/photos/000/022/802/original/IMG_20171205_145207.jpg) ### Overview Often, electronic environmental sensors are just one part of a system that includes: * a [data logger](/wiki/data-logging) * some kind of [water and weather-proof enclosure](/wiki/sensor-enclosures) * a **sensor of some kind** -- see [Sensors](#Sensors), below And we also have to consider: * how to **configure the logging program** & **[connect to the chosen sensors](/notes/warren/12-06-2017/help-document-how-to-connect-different-sensors-to-a-data-logger)** * how to [download data](/wiki/data-logging#Download) * how to [visualize](/tag/visualization) data * how to [design experiments](/tag/experimental-design) using these techniques It's hard work writing good documentation. Let's team up and share as much of the above as possible -- many of these steps are either not device-specific, or are at least very helpful **if written in a way that supports use across projects**. **** [![coqui.png](https://publiclab.org/system/images/photos/000/022/801/large/coqui.png)](https://publiclab.org/system/images/photos/000/022/801/original/coqui.png) ## Getting started If you have never used an electronic water sensor before, try the Coqui project, which is specifically designed for folks who are just starting out. [Build a Coqui](/wiki/coqui) - a simple device to read a sensor via an audible tone. The Coqui is also a stellar example of how to document a project. (above photo by @akshaya) **** ## Choosing Sensors Often the first step is to **look for a sensor for what you're hoping to measure.** Below we're collecting info on different kinds of water quality sensors, and their: * cost * sensitivity/accuracy * links and documentation Can you afford a sensor? Can it detect what you're looking for? Where can you learn more about it? And here's a longer collection of many different sensors ([add to this list here!](/notes/warren/12-06-2017/help-collect-environmental-sensors-probes-on-a-shared-list)): See and [edit the full spreadsheet here](https://docs.google.com/spreadsheets/d/1UwjRqU8kHTwEcnDdO2Zxkr8zkFkaGfyePJ-cdnxJzw0/edit?usp=sharing) ### To be added * See this [great list of sensors from the KnowFlow](/questions/rockets/07-10-2017/how-accurate-is-the-probe) * [the Wheestat](/wiki/wheestat-user-s-manual) can be plugged into a datalogger * we should go through the above list and see which are Arduino-compatible - add to the "Interface" column * Figaro electronic #hydrogen-sulfide sensors [here](/notes/warren/9-19-2011/prototype-h2s-sensor) Are there others you're interested in? Please add them to the list here and to the linked Google Doc! (below are some not listed above yet) - transparency - chemical oxygen demand - COD - phosphate - total dissolved solids - TDS - Hardness - Lead - bacteria - fluoride heavy metal [prompt:text:ie temperature] **** ## Questions [questions:water-sensors] **** ### Connecting sensors Most of the [data loggers](/wiki/data-logging) on this site are Arduino-based (#arduino) while some are Raspberry Pi-based (#raspberry-pi). Vernier has a lot of good resources on connecting their Arduino-compatible sensors, with example code: https://www.vernier.com/engineering/arduino/ As we build out resources for connecting different sensors or different types of sensor interfaces (i2c, analog, etc), let's think about how best to list those guides and support materials here. Help add activities below for connecting specific sensors to [different data loggers](/wiki/data-logging), and pitch in on [researching how these connect here](/notes/warren/12-06-2017/help-document-how-to-connect-different-sensors-to-a-data-logger). [activities:connecting-sensors] **** ### Analog methods Even though this wiki page is labeled "water sensors," the most accessible modes of measuring water quality parameters are often **analog, non-digital methods** where you directly observe water (e.g. using a secchi disk to assess turbidity) or collect a sample and test it with a visual method (e.g. color-change pH strips). Several analog tools are included in the spreadsheet, and please add more! ### Hybrid approaches and enclosures In some cases, it may be possible to couple a commercially available **probe** sensor with a DIY **data logger** (such as the Riffle, https://publiclab.org/riffle) and an water-tight **enclosure** to create a lower-cost deployable sensor. Deployable sensors can be extremely useful for long-term monitoring, monitoring in places that are difficult to access frequently, or to document fluctuations in water chemistry with greater temporal resolution. ...
Author | Comment | Last activity | Moderation | ||
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jhondue123456 | "https://www.google.com/ " | Read more » | 8 months ago | |||
StroudCenterScott | "Great question, @bhamster. You can send data to the Monitor My Watershed data sharing portal from any Arduino-framework device. Here is a simple, l..." | Read more » | almost 3 years ago | |||
bhamster | "Thanks so much for sharing this @StroudCenterScott! I had heard about the Mayfly data logger from someone who was using it to monitor a stormwater ..." | Read more » | almost 3 years ago | |||
alejobonifacio | "Wow! This is so interesting... Thanks for tagging me @bhamster! :hugs: " | Read more » | over 3 years ago | |||
newwayre | "we are real estate company dubai, we provides you the facilities of selling your property in a good rate. #1 real estate company in dubai. https://..." | Read more » | over 3 years ago | |||
bhamster | "That would be terrific, thank you! @alejobonifacio, tagging you in case you're interested in sensors for redox potential and dissolved oxygen. " | Read more » | over 3 years ago | |||
jesseslone | "Yes, those spikes are aeration. Later I dropped the DO sensor and used ORP to control the aeration cycles. Nutrient removal is always a game of d..." | Read more » | over 3 years ago | |||
bhamster | "Oooh this is very cool. Super clear dashboard graphs! Are those tall spikes when the water was aerated? And yes, it'd be great if you could join a..." | Read more » | over 3 years ago | |||
jesseslone | "Yes, it did end up correlating. I looked back over this article and realized I should probably post a follow up. As expected, you start to get a ..." | Read more » | over 3 years ago | |||
bhamster | "Thanks for the reply and willingness to answer my questions @jesseslone! I was wondering--did the DO and ORP readings end up correlating with bacte..." | Read more » | over 3 years ago | |||
jesseslone | "I'm not using it currently, but it ran for a long time unattended. Let me know if you have any other questions, I'm happy to answer them. " | Read more » | over 3 years ago | |||
bhamster | "Hi @jesseslone. This post is a few years old now, but I was curious if you're still using this sensor? Thanks! " | Read more » | over 3 years ago | |||
liz | "Hi @wln215 , I just spotted this question and wanted to at least respond in appreciation for you for answering other people's questions. :slightly_..." | Read more » | over 4 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 » | about 5 years ago | |||
emawatson12 | "I apapricate your content Ema Watson " | Read more » | about 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 » | about 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 |