Development and Calibration of a Digital Recording System for Automation of Runoff Measurement

Field runoff estimation by the use of integrated circuit (ICL7106) digital converter is a new concept of surface water flow measurement in the sub-Saharan Africa. It is a very efficient, low power analog to digital (A/D) converter. A runoff collector of area 1m^2 and depth 30 cm was constructed, and a discharge pipe of 2.5 cm diameter and length 60 cm connects the runoff collector to the runoff storage tank, 30 cm x 30 cm x 30 cm in dimension. Both the runoff collector and the storage tank were made of metal sheet (18 gauge). The active devices used for the construction of the digital sensing device include decoders, display driver, reference resistor, a clock, sensor, liquid crystal display (LCD) and lCL7106. The lCL7106 was designed to interface with a liquid crystal display (LCD), which includes a back-plane drive. This digital recording system was designed to measure the amount of runoff that flow into the runoff storage tank through the discharge pipe, such that the resistor sensed runoff according to the level of water in the tank. The sensor divides the reference voltage Vr in ratio to the value of resistance (R1). This varying voltage is now converted to digital readout by A/D converter with respect to liquid crystal display (LCD). The equipment was calibrated with the aid of standard measuring cylinder (1000 ml). It was observed that runoff within the range 7500 ml to 42000 ml could be adequately measured using the digital device. This research development is useful in weather forecasting, flood studies and hydrological analysis in natural science studies.

並列關鍵字

Analog ； catchmant ； digital ； electronic sensor ； runoff and storage tank

國際替代計量

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