Weed-Resistant Propeller-Meter System

Seeking a flow-measuring method that could exploit the usual farm delivery pipe placed under the canal roads common to irrigation canal systems, tolerate trash and weeds, and offer low maintenance and operating costs, we quickly discarded high-tech, high-cost meters in favor of modifying a reverse propeller-meter system that had previously fouled in its original presentation. The modifications successfully handled weed and moss fouling while preserving the basic accuracy of the original meter system. The modified system uses specially configured trash-resistant appurtenances enabling operation in heavy moss and weed environments and flow-profile conditioning accessories that are also trash resistant to condition flow jets from an upstream control gate and preserve meter accuracy. The system has operated in an active farm installation through several irrigation events since September 2011. It provides electronic output for data recording, transmission, or mechanized irrigation control. The system functioned successfully in adverse weed and moss conditions while maintaining its basic accuracy of +/-2% to 3%.