关键词: 流量观测, 排水沟流量, 沉井结构, 水泵控制, 浮子开关, 单片机

Abstract: To monitor the drainage flow by caisson volume method, a caisson linking with the bottom of the drainage ditch is installed. During off-hours, the caisson is a storage well, and the ditch water flows to the downstream through the caisson. Main equipment of the monitoring system includes a submersible pump, a two-float liquid level switch, as well as control and measuring single-chip microcomputer. During working time, the water stored is pumped out until it drops to the lower float liquid level switch, then all the ditch flow goes into the caisson, indicating another water storage process. By measuring the volume between the upper and lower float liquid level switch as well as the time of filling-up, the flow rate of the drainage ditch can be obtained. After the caisson is fully filled, the ditch water flows through the upper part of the caisson and gets back to normal drainage.

Key words: flow observation, drainage flow, caisson structure, pump control, float switch, single-chip microcomputer