A Rainfall-pH-meter and Dry Precipitation Sampler

A microprocessor-based rainfall-pH-meter equipped with a dry precipitation sampler is presented. The battery powered system includes a water-sensing sensor and containers for wet and dry deposition. A mechanical cover is used to cover the dry deposition container when rainfall occurs and to cover the wet container when there is no rainfall. A temperature compensated pH-meter is used to measure pH of the collected rainfall. An optoelectronic sensor that uses near infrared radiation is used to detect the occurrence of rainfall. The pH values are determined whenever 0.5 mm of rainfall are collected. Rainfall depth, duration and intensity values can be determined from recorded data. The advantages of this system are: (i) low cost, (ii) low energy consumption, (iii) continuous data on rainfall depth, duration and intensity, (iv) continuous pH data trends during rainfall events and, therefore, (v) potential for use in networks for monitoring atmospheric deposition.