Abstract
Inexpensive, Robust Water Stage Sensor for Rural Community Footbridges
American Geophysical Union Fall Meeting (San Francisco, California, USA, 12/15/2014 - 12/19/2014)
12/15/2014
Abstract
Footbridges across streams and rivers provide rural communities in many countries essential access to hospitals, schools, and economic opportunities. Without these, communities experience isolation during the rainy season. However, many of these bridges are subject to immersion at times, and there is a need for sensing the river stage before venturing onto a bridge. We have developed an inexpensive, robust, self-contained sensor that meets this need. A two-wire electrical cord, purchased in bulk from a home improvement supplier, is the basic sensing element. The two conductors of the cord form a transmission line capacitor. The cord is suspended below the footbridge and the capacitance is a function of the fraction of the electrical cord that is immersed in water. The cord/capacitor is part of the timing element of an electronic oscillator circuit. As the water level rises, the capacitance and oscillator frequency decrease. The oscillator frequency is measured with a microcontroller. The microcontroller calculates the corresponding water stage and displays it on a small LCD display. The electronics are contained in a 12×7×7 cm watertight container. Four AA batteries power the sensor. The device has calibration features to accommodate different types of electrical cord.
Details
- Title: Subtitle
- Inexpensive, Robust Water Stage Sensor for Rural Community Footbridges
- Creators
- David J McDermot (Author) - University of IowaKathryn Langenfeld (Author)A Allen Bradley Jr (Author) - University of Iowa, Civil and Environmental EngineeringAnton Kruger (Author) - University of Iowa, Civil and Environmental EngineeringJames J Niemeier (Author) - University of Iowa, IIHR--Hydroscience and Engineering
- Resource Type
- Abstract
- Conference
- American Geophysical Union Fall Meeting (San Francisco, California, USA, 12/15/2014 - 12/19/2014)
- Language
- English
- Date published
- 12/15/2014
- Academic Unit
- Civil and Environmental Engineering; IIHR--Hydroscience and Engineering
- Record Identifier
- 9984580558402771
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