USING THE ARDUINO MICRO-CONTROLLER TO BUILD CUSTOM INSTRUMENTATION FOR GROUNDWATER APPLICATIONS

Hydrogeologic data collection often requires specialized equipment and instrumentation. Often the equipment for a specific need is not available or is prohibitively expensive. A solution to this issue is for the researchers to create their own equipment. This has become easier due to the Maker Movement, a cultural movement where hobbyists create and share “cut and paste”, do-it-yourself (DIY), open source hardware and software. The result is that hydrogeologists can design and build specialized instrumentation quickly and at low cost for specific applications. While this solution can be effective, it is unlikely to replace fully engineered commercial solutions because of the environmental demands and complicated instrumentation of some hydrogeologic measurements.

We have built four systems using the Arduino microcontroller platform. They are a groundwater-quality data recorder with Geographical Positions System (GPS), an infrared and contact temperature sensor with data storage and GPS, a temperature flux meter with data storage, and an electromagnetic sensor (Geonics EM31) with data recorder and GPS. We constructed the groundwater quality system to record pH, temperature, fluid conductivity, dissolved oxygen, chloride, nitrate, GPS location, and time with the sensors placed in a flow through cell. Issues with this system included understanding the limitations of the sensors and maintaining a good GPS signal through the many wires in the enclosure. We used the infrared sensor system to measure stream temperatures and will use it to provide verification data for a UAV-mounted infrared camera. The temperature flux meter can record seven temperatures with time and depth and will be used for groundwater flux measurements. The EM31 sensor data recorder allows us to store GPS locations and ground conductivity readings at 2-second intervals.

We have been successful designing and building our own instruments for the applications described above. These instruments have allowed us to collect data at a quality, quantity, and cost that is otherwise not possible. Although we recommend consideration of a DIY approach, more complicated instrumentation and more challenging environments are likely to require an engineered and commercial solution.