Doppler Water Velocity Sensor

Doppler velocity sensor utilizes doppler effect principle to measure sewer fluid velocity in open channel or partial and full pipe. With built-in sensing elements for temperature and pressure, the doppler flow meter can measure velocity, level, water temperature and flow rate.

Encased with engineering plastic enclosure, the doppler velocity sensor is completely sealed without ports and orifices. Without moving parts, there is no problem of silt blocking and grass entanglement. The probe is also solid and durable, and meanwhile it is easy to install and use. It can be installed under the water and the default depth is 10m, bigger depth (up to 100m) can be customized.

With velocity sensing point at front, doppler velocity sensor doesn’t damage flowing field, and feature high accuracy, wide range, high resolution, quick response time, etc. It can measure instant velocity and average velocity of at weak flow side or strong flow side. Linearity measurement and flow velocity calibration curve are not easy to be changed.

The doppler velocity flow sensor only has 3cm height and it can start measurement once probe submerged in water. When water level is 10cm higher than doppler sensor, it can start to work normally, thus it is especially suitable for application with low water level.

The doppler flow sensor can monitor velocity, level and temperature at the same time. If equipped with electronic converter, the doppler flow meter can easily calculate instant flow rate and flow totalizer with universal standard, e.g. full pipe, partial pipe, open channel, etc.. The flow sensors have been widely used for irrigation open channel, municipal sewer, hydrological basin and other applications.


  • Velocity, level and temperature integrated into a small size body. The small sensor itself is a complete product, and RS485 Modbus for values of velocity/level/water temperature
  • External electronic flow converter optional to easily calculate flow rate (instant &totalizer), meanwhile analog output available.
  • Compact size design and suitable for low level application, e.g. from 18mm level.
  • No need to build special flume and weir, saving installing cost. Also ideal for projects where flume and weir are difficult to build.
  • Comparing with traditional ultrasonic flume open channel flow meter, doppler flow meter has higher accuracy, more reliable and simple to install.
  • Wholly electronic design with strong anti-interference, no mechanical parts, no moving parts, no blocking problem, longer working life.
  • Wide power supply, low power consumption, suitable for solar powered or battery powered
  • Linearity measurement and have been calibrated before delivery. No need to do calibration after long-term using.
  • Developed on ultrasonic doppler shift frequency, low velocity startup, higher accuracy, wide measurement range, etc.

Technical Specification:

  • Flow Velocity Range: 0.02~5.00 m/s(Bigger velocity optional)
  • Flow Velocity Accuracy: ±1.0%±1cm/s
  • Water Temperature Range: -10~60 ℃
  • Temperature Accuracy: ±1℃
  • Water Depth Range: 0.03~5m (Max depth optional)
  • Depth Accuracy: 0.5%±0.5cm
  • Power Supply:8~15VDC
  • Power Consumption(12VDC Power):20-65mA (Peak value<=40mA) (Sleeping mode:<=20mA)
  • Data Refresh Cycle: 6-60 Second (Default: 8S)
  • Protection Class:IP68
  • RS485(Modbus-RTU): Output datas of flow velocity, water level, water temperature
  • PH value of fluid: PH:6-8
  • Turbidity: Solid impurities in the fluid is less than 20mg/L
  • Dimension of Sensor: L:250mm,W:70mm,H:30mm


  • The doppler sensor is a complete product with RS485(Modbus) output. It can't measure flow rate
  • If require flow measurement, we have external electronic converter optional. Of course, user can change their software to calculate related flow rate. This will save cost.
  • Our external flow converter can calculate instant flow rate and flow totalize for certain structure,e.g.pipe,open channel,etc.

Main Specification of Flow Converter

  • 4-20mA Output Output: instant flow rate (External Power Supply)
  • Instant Flow Range: 1L/S --- 99.99m3/s
  • Flow Totalizer Range: 0.1 --- 999999m3
  • Display Screen: LCD display
  • Protection Class: IP65
  • Power Supply: AC/DC