Technical Note: A Simple Method to Measure the Flow Rate and Volume from Tile Drainage Pump Stations

摘要

Measurement of flow characteristics both in and out of tile drainage pump stations has always been difficult. In a typical pump station, float controls are used to turn the pump on and off. Although the flow into the sump is continuous, the pump discharge is intermittent making it difficult to accurately measure with standard flow measurement devices. Indirect measurement of flow and volume was accomplished using a current switch connected to an event datalogger. The pump-on and off periods were time stamped to the nearest half second. These data, when combined with the pump characteristic curve, the sump storage volume, and lift distance provided volume and flow rate estimates for the inflow and discharge of a field scale drainage pump station. From April to November of 2008, this method was used to estimate the inflow and discharge from a pump station that handled the outflow from a 20-ha tile drained field. The accuracy of the flow rate estimation was compared to the values obtained from the manufacturer's pump curve. The maximum difference was 3.5% between the two values