翻斗流量计测量径流小区流量的精度与校正

Accuracy and Calibration of Tipping Bucket Flow Meter in Flow Rate Measurement of Runoff Plots

随着我国大规模水土流失监测工作的开展,径流小区径流量的自动监测越来越受重视,而翻斗流量计是备选设备之一。为了明确翻斗流量计用于小区监测的适用性,依据已有的小区资料,设计0.1、0.5、1.0、1.5和2.0 L/s共5个流量,0、50、100、300和500 g/L共5个含沙量,通过与径流桶测量数据对比,测定翻斗流量计的测量精度。结果表明,当流量与含沙量较低时,翻斗流量计所测径流量精度较高;随着流量增大,翻斗流量计测量结果比实际值偏小,且误差逐渐增大;随着含沙量增大,翻斗流量计测量结果比实际值偏大,且误差逐渐增大;这些变化有很好的规律性,可以通过线性回归公式进行校正获得较好的测量精度。

Along with the development of soil and water loss monitoring conducted in a large scale in China,the automatic monitoring of runoff rate of runoff plots has been taken more seriously and lipping bucket flow meter is one of the optional equipment.In order to clarify the applicability of tipping bucket flow meter used in plot monitoring,it designed 5 flow rales of 0.1,0.5,1.0,1.5 and 2.0 L/s and 5 sediment concentrations of 0,50,100,300 and 500 g/L,according to the existed runoff plot data and measured the accuracy of the flow meter through comparison with the measured data of normal collecting tank.The outcomes show that a) the accuracy measured by tipping bucket flow meter is higher when the input flow rate and sediment concentration are lower;b) along with the increase of flow,the actual value is higher than that of the measured data and the error is gradually increasing;c) along with the increase of sediment concentration,the actual value is smaller than that of the measured data and the error is gradually increasing and;d) there is a good regularity for these variations and the measurement accuracy can be obtained through the calibration of linear regression equation.