Some Aspects of Measurement Errors Analysis in Electromagnetic Flow Meters for Open Channels

This paper deals with some problems of measurement error analysis for flow measurement by electromagnetic flow meter. Two main groups of errors are discussed. The first group of errors is caused by various flow parameters which differ from the flow characteristics during calibration. The authors present a new method of errors estimating, called the moving stream method that allows to estimate on error of a flow meter during the design stage much more precisely than classical methods. The second group of errors is caused by a variation of liquid level in a flow channel during flow meters’ operation. Authors propose a selecting an appropriate liquid level as a parameter in designing the exciting coil of electromagnetic flow meter as a best way of that error minimization. Some results of numerical simulation are presented.