Urban drainage networks are responsible for flood control and drainage, sewage collection and transportation in cities. They carry the life safety of a city. And it cannot do without a stable, accurate and easy-to-use traffic detection device. However, traditional monitoring equipment is often affected by installation environment and medium factors, resulting in inaccurate measurements or high maintenance costs, which causes great headaches for many enterprises and maintenance personnel. To address these issues, Aister Doppler ultrasonic flowmeters have developed a “monitoring assistant” that is easy to install, highly accurate, low-power, and maintenance-free – the Doppler ultrasonic flowmeter.