Prediction of Sediment Sampling Error at Nozzle

Abstract

Pump sampling can be an accurate method of measuring suspended sand concentrations. When the flow velocity through the pumping nozzle does not match the local stream velocity, however, an error is introduced. A simple equation is presented that can be used to produce correction factors for this source of error. The equation is successfully compared to data that was not used in the development of the theory. The predictive equation is also adapted to include misalignment of sampling nozzle; the adapted equation is checked against data and used to show that these errors are very small.