Complementary time difference method ultrasonic open channel metering device and metering method

The invention provides a complementary time difference method ultrasonic open channel metering device and method.The device comprises an integrating instrument, a water level sensor and a plurality of flow velocity sensors, the integrating instrument is fixed in a case on a vertical rod beside a channel and connected with the water level sensor and the flow velocity sensors, and the water level sensor is connected with the flow velocity sensors. The water level sensor is hung at the tail end of the cross arm of the vertical rod and is perpendicular to the channel bottom; the plurality of flow velocity sensors are uniformly distributed on the upstream and downstream sides of the open channel; the integrating instrument comprises a processor, and the processor is used for judging whether the current channel environment has a flow velocity measurement environment or not according to the water level information collected by the water level sensor and the data collected by the flow velocity sensor, and if not, swi