LOW-COST AUTOMATED RAIN COLLECTOR AND ITS APPLICATION TO THE STUDY OFWET ONLY DEPOSITION IN SAO-PAULO (BRAZIL)

An automatic rain collector was developed with emphasis on simplicity, construction with readily available low-cost materials, inexpensive m aintenance and reliable operation at temperatures above freezing point . The rain sensor is of the heated AC conductometric type and the circ uit includes electronic protections against false triggering by electr ical transients. With this collector, the first studies of chemical ch aracterization of wet only deposition were made in Sao Paulo over the period of November 1988 to June 1990. Results are presented and compar ed with previous total deposition studies. For this period the volume- weighted mean values of the pH and conductivity were 4.6 and 19 mu S c m(-1), respectively.