| Abstract: | Hydrologic investigations typically involve the collection of water level measurements at discrete points in space and time. The high cost of commercial electronic recorders can be a burden. We have developed an inexpensive (～$200) electronic water level recorder consisting of a Motorola microcontroller, a clock, memory, pressure transducers, and associated circuitry. The instrument is powered by a 6-V battery. These devices, each capable of monitoring up to eight channels of analog input, are presently providing continuous monitoring of nested piezometers, tide gauges, and rain gauges in hydrologic studies at the Savannah River site and the North Inlet (South Carolina) Long-Term Ecological Research (LTER) site. The instruments can be custom tailored to record water levels at any specified time interval, or whenever the water level changes by a specified amount, and can store up to 32,000 water level observations. These instruments have been used to conduct slug tests and can be configured to monitor observation wells for pumping tests. Simplicity of construction and availability of components offer hydrologists an inexpensive but reliable method of water level recording. Several examples of the use of this instrumentation in diverse hydrologic settings are described. |
