随着煤炭开采量增加和开采层位愈来愈深，煤矿井下突水事件发生概率增大，地下水害已成为威胁煤矿安全生产的主要因素。井下明渠流量监测作为煤矿的常规任务为地下水害预警分析提供了重要的基础资料和历史参考依据。但传统的堰式和槽式流量计在井下明渠底部淤泥沉积的情况下测得的流量值与实际值存在严重偏差。为了精确实时测量井下明渠流量，研发精度更高、实时性更强、适合井下环境的明渠流量测量仪具有重要意义。 文章研究了各类传统堰式和槽式明渠流量测量仪的测量方法以及超声波测距技术，创新性的设计出将超声波测距与传统堰槽式测量方法相结合的新型矿用堰槽式明渠流量测量仪并运用于井下明渠流量测量。该测量仪主芯片选用MSP430F5438，利用两个自发自收的超声波传感器和精确计时芯片TDC_GP2分别测量出明渠上方固定点到明渠水面的距离和水面到渠底淤泥表面的距离，由此推导出实际淤泥层的厚度，再使用传统的堰板法或槽式流量计算公式在除去淤泥厚度的基础上计算出实际的流量值。该流量仪还具备温度补偿、液晶显示、RS485通信等重要模块，其驱动软件使用C语言编写，并且具有定时采集数据、低功耗休眠等功能。 经过实验室模拟环境测试，该矿用堰槽式明渠流量测量仪软硬件系统能够达到预设精度和实时性要求，并且符合矿用安全标准。对煤矿井下明渠流量测量和水害预警有较好的效果。

With the increase in the amount of coal mining and mining horizons increasingly deep, the probability of mine water inrush increases. Underground water harm threat has become one of the main factors for coal mine safety production. As the routine tasks, underground open channel flow monitoring provides coal mine with important basic information and historical reference used to analysis the underground water harm. But the traditional weir and slotted flowmeter could cause serious deviation between measured value and the actual value in the case of sludge deposit in the bottom of underground open channel. So, designing high-precision and more real-time underground open channel flowmeter is of great significance to measure the underground open channel flow accurately and timely. This paper has raised an innovative flowmeter that combine ultrasonic ranging technology and traditional weir trough measurement methods based on the research of various measurement methods used by traditional weir trough open channel flow measuring instrument as well as ultrasonic distance measurement technology. This flowmeter was specifically designed for underground coal mine use. The MSP430F5438 was selected to be the microcontroller of this flowmeter. In order to calculate the actual flow value, we should firstly measure the distance between the water surface of open channel and fixed point above the open channel as well as the water surface and sludge surface. They were measured by precise timing chip TDC_GP2 and two ultrasonic sensors which can transmit and receive by themselves. Secondly, the thickness of actual sludge layer can be deduced by the two distance mentioned above. In the end, the actual flow value could be worked out by traditional weir trough measurement methods on the basis of the thickness of the sludge was removed. This new measuring instrument also includes temperature compensation, LCD, RS485 communication, and other important module. This system was programmed in C language and it also has the function of regular data collection and low-power sleep. The laboratory simulation environment test show that both the software and hardware of this mine weir trough open channel flowmeter is able to reach the preset accuracy and real-time requirements. It is also in line with mine safety standards. This mine weir trough open channel flowmeter was proved to have better results in coal mine flow measuring and water damage warning effect.