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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
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 » about 5 years ago
gretchengehrke "That's so great, Shan! " | Read more » about 5 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 » about 5 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 » about 5 years ago
gretchengehrke "@shanlter, this is great! Have you seen the spreadsheet on the page? There are some other options there listed..." | Read more » about 5 years ago
rockets "yes, that's better than mines " | Read more » about 5 years ago
warren "Hi, @rockets -- maybe refining the title could be helpful here; I hope you don't mind but as I'm an admin, I changed it to How accurate are KnowFlo..." | Read more » about 5 years ago
rockets "The probe accurate is list below: 1 Gravity: Analog Electrical Conductivity Sensor / Meter For Arduino Operating Voltage: +5.00 V PCB Size: 45 × 32..." | Read more » about 5 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 » almost 6 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 » about 6 years ago
ggallant "I parked the openscad design files at If there is a better place, such a..." | Read more » about 6 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 » about 6 years ago
ggallant "I have decided to suspend my current turbidity sensor and instead adapt yours to my base station. If it is of interest I have modeled the mechanica..." | Read more » about 6 years ago
bhickman "Hi ggallant. Sounds interesting. I'm trying to picture your design, but I'm not sure if I have it right. Can you post a picture? I definitely thin..." | Read more » about 6 years ago
ggallant "My current led and sensor boards are 6 sided and designed to attach to hardware store 3/4 plugs with plenty of epoxy and silicone sealant. Next rev..." | Read more » about 6 years ago
bhickman "Hi ggallant. I'm using Texas Instrument's Tiva microcontroller which has a couple pins that allow you to tap into the bus power (5V at 1A). For sho..." | Read more » about 6 years ago
ggallant "The LED is specified at 100ma. This "should" need a driver transistor. Outputs pins from the CPU are typically rated at 25ma max. " | Read more » about 6 years ago
bhickman "Hi gretchengehrke, thanks. To answer you questions: (1) I'm using this LED and this photodarling as the detector. The LED has a maximum output at 8..." | Read more » about 6 years ago
gretchengehrke "Hi @bhickman, this is great. Other folks (mostly @donblair) have been working on developing a turbidity sensor too. I have a couple of questions wi..." | Read more » over 6 years ago
bhickman "Hi ggallant. To answer your questions: 1. Yes, the unit is intended for submerged operation. So far I have only had it submerged in beakers in the ..." | Read more » over 6 years ago
ggallant "Couple of questions: 1. Is the unit intended for submerged operation? 2. Extended deployment? 3. How is the water cycled to the chamber? 4. What ar..." | Read more » over 6 years ago
donblair "Yes, nice! In the picture, it looks like one could place a little cuvette right there in the middle and assess the turbidity :) " | Read more » almost 7 years ago
warren "At the Somerville coworking yesterday it occurred to me how similar this is to the optical particulate monitor designs!" | Read more » almost 7 years ago
mathew "I was worried about those o-rings... the silicone, while durable, is flexible and doesn't stick down well. Next option is to try poking through a..." | Read more » almost 7 years ago