Applications of Ultrasonic Doppler Flow Velocity Meters

1. Product Introduction

Ultrasonic Doppler flow velocity meter is a device used to measure the flow velocity of water in pipes, channels, or rivers, mainly applied in the following areas:

· Flood disaster monitoring 

      · Sewage discharge 
      · Natural streams and rivers 
      · Municipal water supply and drainage
      · Water loss/infiltration monitoring 
      · Irrigation flow monitoring 
      · Estuary and tidal studies 
      · Fisheries/water conservancy 
      · Coastal erosion studies
      · Culvert flow monitoring 
      · Road drainage monitoring
      · Canal flow studies 

· River flow monitoring

2. Working Principle

The sensor has two transducers, one for transmitting and one for receiving. When the sensor is facing directly against the water flow direction, i.e., for upstream measurement:

      1. When the water is still, the received frequency is the same as the transmitted frequency.
      2. The faster the flow velocity, the faster the frequency received by the receiving transducer, which will be higher than the transmitted frequency.
      3. The slower the flow velocity, the slower the frequency received by the receiving transducer, but it will still be higher than the transmitted frequency.
      From the above, the flow velocity and flow direction can be calculated through hardware and software.
      During installation and use, the sensor must be positioned directly facing the water flow direction.

3. Technical Parameters

      Measurement types: Flow velocity, water depth,
      Application: Online measurement
      Flow velocity measurement range: 0.02 m/s to 5.00 m/s (minimum water depth: 15 cm);
      Flow velocity measurement resolution: 1 mm/s;
      Flow velocity measurement accuracy: ±2 to 3% of measured flow velocity;
      Water depth measurement range: 5 m, 10 m;
      Water depth measurement resolution: 2 mm 
      Water depth measurement accuracy: ±0.5%;
      Power supply: 11 to 14 VDC;
      Output signal: MODBUS RTU protocol;
      Sensor cable length: 10 meters;
      Measured waterway types: Pipes, channels, natural streams, rivers;
      Liquid pH requirement: pH value between 5 and 7.
      Liquid temperature requirement: 0 to 60 °C, non-freezing
      Liquid pressure requirement: 1 standard atmosphere under natural conditions
      Note: Flow velocity cannot be measured when water is frozen or near freezing.

4. Product Images

 5. Product Installation

1. Channels or natural rivers
     Try to select a straight channel with a standard cross-section that satisfies the requirement of 10 times the channel width upstream and 5 times downstream. If this requirement is not met, the water flow may not be very stable, which could result in measurements that are higher or lower than actual. In such cases, correction is needed, usually by applying a correction factor (derived from on-site calibration) or adjusting the installation position.

2. Manhole sewers

In sewers, if there is no sediment, install the sensor at the center of the pipe bottom. If there is sediment, install the sensor next to the sediment. To prevent the sensor from shifting due to water flow impact, a base is provided at the bottom of the sensor to secure it to the pipe. Additionally, the sensor should be installed inside the sewer near the manhole, which facilitates both installation and maintenance/ replacement.

6. Field Cases

Installation site at Minqing Linli Reservoir

Installation site in Kunming, Yunnan

Fuzhou Dayu Electronics Technology Co., Ltd. — Manufacturer of ultrasonic Doppler flow velocity meters, always committed to providing customers with quality products and excellent service solutions. If you are interested in the above ultrasonic Doppler flow velocity meter or have any questions, please click to contact our online customer service QQ: 2187169532, 24-hour service hotline: 0591-28082552. Fuzhou Dayu Electronics will serve you wholeheartedly!