降雨径流模拟试验中小流量电测方法的研究

APPROACH TO AN ELECTRICAL MEASUREMENT OF LOW-DISCHARGE IN THE SIMULATION EXPERIMENT OF BAINFALL-BIINOFF

本文就电阻法测流的电压-流量非线性关系进行了探讨,提出了线性处理的方法,并设计了具有良好线性关系的测流槽。加上电测线路的高稳定性与测流系统较优的讯噪比,使得实验室降雨迳流模拟实验的分析研究十分方便。另外,还解决了由于水质不纯而导致的电极极化效应。最后,文章给出电阻法测流与体积法的精度对比结果。

The present paper deals with an elementary principle of a new measurement of runoff with very low discharge by means of resistance measuring-flow, and the nonlinear Flow-Voltage relationships with the resistance measuring-flow. A method of linearization handling is provided to make the Measuring-Runoff Flume in a better linear relationship. The analysis of dynamic response charactertics of Resistance Measuring-flow Flume is based on system dynamics theory, as a result, system parameters ωn and ζ are obtained for judging regulating-storage of measuring-flow device’ The Measuring-flow Flume has been applied to measure small discharge in the Hydro-logic Runoff Laboratory. As it belongs to instantaneous flow-rate measurement method, the runoff hydrography measured is very clear as regards its duration, peak discharge, lag of time, and relevant parameters. In addition, the device has a higher stability of electronic circuit and better signal-to-noise ratio, and the problem of electolytic action at electrodes surface due to impurity of the water has been solved, so it is more convenient to make research of the rainfall-runoff relationship in laboratory. Finally, in this paper a comparison of cumulative sum of hydrography from Resistance Measuring-flow Flume with cumulative water-volume-method is given, and satisfactory results have been obtained.