A DATA ACQUISITION SYSTEM FOR SPRINKLER UNIFORMITY TESTING

The scope of this work was to develop and evaluate a data acquisition system (DAS) to automate sprinkler uniformity distribution testing. The system was designed to perform indoor tests for low and medium pressure sprinklers using a two radii collector pattern. The data acquisition system consisted of a PC/AT 386 computer connected to an A/D converter, which received signals from 16 collector-transducer devices. The measuring principle of those collectors was to use the output of load cells to estimate the volume accumulated inside each collector. Four tests of the Naan 501-U sprinkler were conducted to evaluate the system performance. Weight readings were taken at 30, 60, 90, and 120 min during each test. The average volume weight readings taken at the end of the tests (120 min) were compared to volume values estimated using a digital scale. Those readings were used to create an overlapping grid pattern for a 6 m (19.7 ft) ×6 m (19.7 ft) sprinkler spacing. Statistical parameters and uniformity coefficients were calculated for both methods (DAS and scale). Sprinkler discharge and operating pressure were monitored by transducers connected to the system. No statistical differences were found between recording methods (P < 0.05). The same conclusion could be made for the uniformity coefficients. The maximum standard deviation of measurement dispersion for the data acquisition system readings was 0.35 mL (0.01 oz). The results showed that the DAS is a reliable system for sprinkler uniformity testing using a radius pattern. The developed automated system proved to be easy to install without requiring specific skills to assemble.