Water Sensors
question:water-sensors

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
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 » almost 2 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 » over 2 years ago
emawatson12 "I apapricate your content Ema Watson " | Read more » over 2 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 » over 2 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 » over 2 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 » over 2 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 » over 2 years ago
mimiss "Please add any other things you can remember @charlotte_clark and @rollinrenola! " | Read more » over 2 years ago
warren "Thanks! I'd guess that's true of some of #dfrobot / #knowflow sensors too, since several of theirs ship with buffer and are off-the-shelf probes co..." | Read more » over 2 years ago
wln215 "I've notices that if these pH meters are left sitting out, or if they get used frequently enough, they need calibration. These sets come with buffe..." | Read more » over 2 years ago
warren "For one, these sensors don't seem to log data, but they're so easy to use otherwise that they seem pretty good for a workshop, for example! cc @ch..." | Read more » over 2 years ago
DitchOntologist "You might find this thread helpful; it lists open-source packages and code for "cleaning" environmental time series data: https://twitter.com/amali..." | Read more » almost 3 years ago
belkinsa " Thank you @MadTinker, I updated the page with that info, hopefully it's right. " | Read more » about 3 years ago
MadTinker " @belkinsa I’d strongly suggest the Winkler test for monitoring DO. It’s easy, can be done reliably by 14+ yr old kids. Works on lakes, rivers, etc..." | Read more » about 3 years ago
belkinsa "Sorry for the delay. I was thinking that the data could be used for monitoring rather than education because that data could be used as a red flag...." | Read more » about 3 years ago
stevie "Hi @Belkinsa ! What are you hoping to use the data for? We recently worked with one of the LaMotte kits to talk about different water quality param..." | Read more » over 3 years ago
MadTinker " do not use DO sensor On a monthly period, at a number of sampling locations in the watershed, air/water temperature are collected and: DO, Ha..." | Read more » over 3 years ago
joyofsoy "These answers came from Twitter user @Sulfur_Blue on a tweet I shared through the Public Lab Twitter account: Consider overall costs / maintenance..." | Read more » over 3 years ago
Ag8n "My background is mostly industrial- specifically pharmaceutical. So much of the testing was guided by something like The USP. The instruments were..." | Read more » over 3 years ago
belkinsa "Thank you! " | Read more » almost 4 years ago
Ag8n "It's listed on Amazon as the Atlas Scientific EZO-DO. It is listed at $46.00. It talks by uart, so a Pi might work. Atlas Scientific should have ..." | Read more » almost 4 years ago
belkinsa "is it a Pi or something else? Can I have the link/ " | Read more » almost 4 years ago
warren ":+1: " | Read more » almost 4 years ago
vjpixel "InfoAmazonia built a hardware that measure DO. The schematics are online: https://github.com/InfoAmazonia/rede-hardware " | Read more » almost 4 years ago