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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](]( ### 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](]( ## 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]( ### 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: 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, 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
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 3 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 3 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 3 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 3 years ago
charlotte_clarke "Yeah my comment came out odd due to markdown -- the underscore is present in both the Arduino code and the script. I was wondering whether it was ..." | Read more » about 3 years ago
wmacfarl "The script will miss substitutions if the data is coming in too quickly -- I put a bunch of delays in the code to slow it down to a point where it..." | Read more » about 3 years ago
warren "That is really odd. I tried a couple other things but can't figure out why this is happening. In theory it should just be pressing the tab key betw..." | Read more » about 3 years ago
warren "Hmm, the script is: function onEdit(e) { var val = e.range.getValue().toString(); if (val.indexOf('_now') !== -1) { e.range.setValue(Dat..." | Read more » about 3 years ago
warren "Oh, it looks like the sensor is sending "_now" instead of "now"... I wonder is it possible to modify the spreadsheet script to match that? " | Read more » about 3 years ago
charlotte_clarke "We have 4 turbidity sensors up and running thanks to Will's very clear and helpful instructions! Excited to use them for the event tonight. I do h..." | Read more » about 3 years ago
warren " " | Read more » about 3 years ago
warren "I did this! My first error it was a silly mistake - the yellow/red/black cable was plugged in backwards. "apparently" it makes a difference which ..." | Read more » about 3 years ago
EdMallon "Progress with the LED light sensor technique revealed that you can can also measure temperature by timing the reverse-bias charge decay on ANY type..." | Read more » about 3 years ago
EdMallon "With the school year beginning we have some new instructors spinning up their own courses around the classroom logger released earlier this year. ..." | Read more » over 3 years ago
roberts_ecofarm " Really liked the tutorials! " | Read more » almost 4 years ago
EdMallon " I've been experimenting with the Input Capture Unit on our pro mini's 329p processor, and with it you can make ‘High-Resolution’ Sensor Readings ..." | Read more » almost 4 years ago
EdMallon "You can use a Pro Mini (or any other Arduino with an Atmel processor) to measure temperature using only the mcu. I think this is the best "No-Par..." | Read more » almost 4 years ago
EdMallon "A high-school teacher friend asked us for faster build that is less dependent on soldering because they don't have the budget for that kit. So we'v..." | Read more » almost 4 years ago
EdMallon "Dr. Beddow's instrumentation students have been building our EDU logger for more than three years and, based on that experience, we've redesigned t..." | Read more » almost 4 years ago
DoraWest "Pleasant post. I was checking continually this online journal and I am awed! To a great degree supportive data extraordinarily the last part I admi..." | Read more » about 4 years ago
warren " Hi, Ed; thanks for reporting this; we'll take a look ASAP. I've opened an issue for you here if you'd like to provide any other information (for e..." | Read more » about 4 years ago
EdMallon "For some months now I've been unable to upload images to comment posts in this research note. I've tried multiple different browsers. Though the im..." | Read more » about 4 years ago
roberts_ecofarm " @EdMallon Glad to see more video links. The basic logger build videos you did were great. Really helped me. Thanks for continuing to share. " | Read more » about 4 years ago
EdMallon "I finally completed the set of logger build tutorials on Youtube, to go with the screw terminal logger posted in 2017: Pro Mini Logger Build: Bat..." | Read more » about 4 years ago