DEVICE OF AUTOMATIC SAMPLING AND MEASUREMENT OF RUNOFF.

摘要

Present invention offers a cost effective automatic runoff sampler that does not need external source of energy. Time integrated, depth integrated and width representative samples are collected by triangular section interceptors each representing different section of flow over weir. Single interceptor is used in case of V-notch. Intercepted discharge is reduced by means of multi-slot divisor connected to a rectangular section channel or by intercepting through triangular section interceptor in series one down another. A reduced discharge (about 50 lit/hour) by above method is time resolved for each 15 minute intervals by means of funnel on top of a cylinder which is mounted over high torque clock. A slanted tube attached to the base of funnel carries reduced discharge to 96 notches mounted on a circular frame in which each notch receives samples for 15 minutes duration. Discharge from each notch is carried to paired bottle system in which first bottle receives discharge and after filling it the rest passes through nylon or cloth mesh on the top of first bottle. Mesh opening is of 5 micron hence retains sediment of size greater than 5 micron. The partially filtered aliquot goes to second bottle kept in lying position just below first where it create a sort of turbulence through increased speed of flow by means of constricted/reduced end touching the lower wall. After filling to a level rest volume comes out through a tube that goes to a cylindrical reservoir with siphon arrangement The rise and fall in the cylindrical reservoir is recorded against time on a graph paper wrapped over the clock mounted cylinder (whose top supports funnel) by means of stilling well float, float guide and attached pen. Two samples are collected from paired bottle and dried for concentration. Concentration is obtained using mass balance equation and relationship defined between concentrations of flow going to cylindrical reservoir which has been developed by the inventors using wide range of data. Further, weir specific relation between actual discharge and intercepted discharge by means of device are developed and used for estimating missing discharge data by means of data collected through the device invented.