Doppler Velocity Meter for Open Channels, Rivers, and Non-Full Pipe Metering

Precise Perception of Fluid Pulsation: Overview of NiuBoL Doppler Velocity Meter

In smart water conservancy and municipal drainage management, contact fluid monitoring equipment has an irreplaceable position because it can penetrate deep into the water body to obtain real-time data. NiuBoL Doppler velocity meter is a high-precision monitoring device developed based on ultrasonic Doppler principle, which can not only obtain velocity in real time but also integrates high-precision water level sensor and temperature compensation element.

Unlike traditional mechanical rotor velocity meters, NiuBoL Doppler velocity meter adopts pure electronic design throughout the machine, with no mechanical rotating parts. This means it will not lose accuracy due to sediment entanglement or bearing wear during long-term operation, greatly improving reliability in complex water quality environments such as sewage and agricultural irrigation.

Core Working Principle of Doppler Velocity Meter: Ultrasonic Doppler Effect

The core of NiuBoL Doppler velocity meter's operation stems from acoustic physical laws.

• Velocity Measurement: The sensor emits ultrasonic waves of specific frequency toward the water body. When the ultrasonic waves encounter tiny particles or bubbles moving with the flow in the water body, they produce reflection. The frequency of the reflected ultrasonic waves will shift due to the Doppler effect (frequency change). After the internal circuit of NiuBoL processes this frequency difference, it can accurately calculate the point velocity or surface average velocity of the water body.

• Integrated Water Level: The bottom of the device integrates a high-precision pressure water level gauge, which converts real-time water level height by sensing hydrostatic pressure of the water body.

• Flow Synthesis: Combining real-time water level, velocity, and preset cross-section structure (such as trapezoidal channel, circular pipeline), the system automatically calculates instantaneous flow and accumulated flow.

Technical Performance and Specification Parameters of Doppler Velocity Meter

Core Advantages of Doppler Velocity Meter: Guarantee of All-Weather Stable Operation

1. Three-in-One High Integration
   One device simultaneously solves monitoring of three dimensions: velocity, water level, and temperature, without additional water level gauge configuration, simplifying on-site installation layout and reducing overall system construction cost.

2. Anti-Interference and High Protection
   Shell adopts ABS engineering plastic, not only possessing excellent anti-corrosion performance but also effective sealing and waterproofing. Paired with high-quality vent cable, it supports long-term immersion in water without cable water seepage or aging.

3. Low-Power Electronic Design
   Full electronic architecture not only improves measurement stability but also brings excellent low-power performance. Combined with 10-30V wide voltage power supply, it is very suitable for solar-powered field hydrological monitoring stations.

Widely Used Application Scenarios of Doppler Velocity Meter

1. Open Channel and Agricultural Irrigation Metering
   In agricultural water-saving irrigation projects, used for monitoring real-time flow of main channels and branch channels, providing data basis for precise water distribution.

2. River Hydrology and Ecological Base Flow Monitoring
   Monitoring velocity changes in small and medium rivers, especially real-time monitoring of ecological base flow required by river chief system, ensuring rivers do not dry up.

3. Urban Drainage Non-Full Pipe Metering
   In urban stormwater and sewage pipe networks, liquid inside pipes is often in non-full pipe state. NiuBoL Doppler velocity meter, with its sensitive capture ability for low velocity (0.03m/s), becomes the first choice for drainage monitoring.

4. Sponge City and Urban Flooding Monitoring
   Monitoring inflow and outflow of rainwater wells and storage tanks, assisting quantitative evaluation of sponge city construction effects.

Professional Installation and Cleaning Specifications for Doppler Velocity Meter

To ensure measurement accuracy of NiuBoL Doppler velocity meter, scientific installation guidelines must be followed:

Position Selection

• Depth Requirement: Normal installation should ensure sensor is at least 20cm below lowest water level, absolutely not lower than 5cm. If exposed to air, water level gauge will not work properly, and velocity data will be invalid.

• Obstacle Avoidance Principle: Installation position should avoid silt deposition areas, dense aquatic weed areas, and dead water zones on shores. Recommend choosing stable flow direction facing upstream.

Installation Details

• Horizontal Fixing: Use reserved M5 round holes to horizontally fix device on channel bottom plate or bracket.

• Cable Protection: Vent tube inside cable must be exposed to atmosphere (prevent blockage), and cable must not have sharp bends, otherwise it will directly affect water level measurement accuracy.

• Filtering Protection: If water body contains large amounts of branches, stones, or high-concentration sediment, set isolation grid in front of device for coarse filtering to prevent foreign objects from impacting or blocking probe.

FAQ:

Q1: Does Doppler velocity meter have requirements for water quality?
A: There are certain requirements. Doppler principle relies on tiny particles or bubbles in water for reflection. If it is completely transparent pure water (almost no impurities), reflected waves will be very weak. However, river water, rainwater, irrigation water, and sewage in nature all contain sufficient reflective particles, very suitable for use.

Q2: How to deal with large amounts of sediment and deposition in water?
A: During installation, avoid areas with serious deposition. If unavoidable, recommend adding mounting base to raise sensor, and clean regularly. NiuBoL adopts ABS smooth shell, which can reduce attachment growth to a certain extent.

Q3: Can communication protocol be connected to my existing PLC or collector?
A: Absolutely. NiuBoL device supports industry standard ModBus-RTU protocol, performs data exchange through RS485 interface, can achieve seamless docking with most domestic and foreign PLC, RTU, and hosts.

Q4: What is the difference between unidirectional measurement and bidirectional measurement?
A: Unidirectional measurement (0.03-5m/s) is suitable for channels with single flow direction; bidirectional measurement (0.03-10m/s) is suitable for conditions affected by tides, pump station backflow, or other possible reverse flows, can automatically identify and record positive and negative velocities.

Q5: Can the default measurement interval of 3s be changed?
A: Yes. Measurement interval can be set according to your application scenario needs. For river channels with gentle water level changes, interval can be appropriately extended for energy saving; for industrial discharge outlets with dramatic flow state changes, high-frequency measurement can be maintained.

Conclusion:

NiuBoL Doppler velocity meter integrates advanced ultrasonic technology with stringent industrial design, dedicated to providing precise digital records for every drop of flowing resource. Whether in deep mountain rivers or urban dark channels, we provide you with excellent flow measurement experience that is stable, accurate, and free of mechanical maintenance.

Technical Specifications and Terminology Summary:

Communication Protocol: ModBus-RTU (RS485)
Monitoring Dimensions: Velocity (m/s), Water Level (m), Temperature (℃), Flow (m³/s)
Core Material: ABS Engineering Plastic, High-Quality Vent Cable
Wave Principle: Ultrasonic Doppler Effect
Protection Level: IP68

If you have procurement intentions for NiuBoL Doppler velocity meter or need detailed installation and construction guidance schemes, please feel free to contact our technical support team.