New Weighing Mechanism for Precipitation Gauges

Recently developed integrated circuit technology and new reliable load-cell scales have made it possible to develop a battery-operated weighing system to measure and record precipitation electronically on a continuous basis. This system was developed to replace the spring scale and chart and/or potentiometer system that is generally used in the Universal Recording Rain gauge. The load-cell scale system records and stores the depth of water in the collecting receiver at least every 15 min, or as often as every 1 min if 0.25 mm of precipitation has fallen during the 1-min period. These data are later telemetered to a central data storage facility. A laboratory calibration of the load-cell scale showed a very good linear relationship between load-cell output voltage and the weight of water in the receiver. There was no apparent hysteresis shown in the output between loading and unloading the receiver. This load-cell scale is ideal for remote locations because the circuitry draws very little quiescent current and a small solar panel keeps the system's 12-V battery fully charged.