Desenvolvimento e calibração de um pluviógrafo

Abstract

The objective of this paper was to develop and calibrate a float type pluviograph. This pluviograph was constructed with ordinary materials such as polystyrene, styrofoam and pvc pipes. Three points were observed in the calibration: time, volume and intensity. The time is associated to the rotational speed of the motor, the volume with the record of the height of the water inside of the storage tube and the intensity with the volume in relation to the time. The area of collection and of the cylindrical storage tube are respectively 7.47x10-3 and 7.45x10-3 m². With these dimensions, 1 mm of precipitation implies a variation of 1 mm in the height of the water column of the storage tube, which can be obtained by adding 7.47 ml of water. The maximum capacity of record in relation to the volume is 13.2 centimeters, which is equivalent to a rainfall of 132 mm. The pluviograph recorded the intensity data in an appropriate way whereas in the five intensity tests performed, the largest absolute error in relation to the estimated and observed was equivalent to a precipitation of 3 mm.