This Doppler ultrasonic flow meter utilizes the ultrasonic Doppler principle to measure flow velocity and flow rate in open channels. A submersible ultrasonic sensor is installed at the bottom of the channel; the measurement point is located in front of the probe, ensuring the flow field remains undisturbed. It continuously monitors flow velocity and water level (depth) while calculating the cross-sectional area and total flow rate in real time. Integrated pressure and temperature sensors are included, and data regarding flow velocity, water level, and temperature are transmitted via RS485.
Related products: Clamp-on Doppler Flow Meter and Portable Doppler Ultrasonic Flow Meter.
Featuring a split design (with the sensor and transmitter separated), the instrument is ideally suited for rivers, streams, flood control channels, water level monitoring channels, drainage ditches, irrigation canals, and similar open-channel environments. Data is output via an RS485/Modbus interface, with optional 4–20 mA analog signal output also supported.
| Item | Specification |
|---|---|
| Power supply | 10 VDC – 28 VDC |
| Power consumption (RS485, 12 V) | 88 mA ± 1 mA (approx. 1.06 W) |
| Power consumption (RS485, 24 V) | 52 mA ± 1 mA (approx. 1.25 W) |
| Power consumption (RS485 + 4–20 mA, 12 V) | 110 mA ± 1 mA (approx. 1.32 W) |
| Output signal | RS485 / MODBUS standard protocol; 4–20 mA (not fitted by default) |
| Flow range | 1 L/s – 99,999.99 m³/h |
| Water depth (level) range | 0.02–3 m or 0.02–10 m (confirm maximum water depth before ordering) |
| Display interface 1 | Water level, instantaneous flow, cumulative flow |
| Display interface 2 | Water level, flow velocity, cross-sectional area, temperature |
| Flow resolution | 0.0001 L/s |
| Housing material (transmitter) | ABS (split type) |
| Sensor material | POM |
| Sensor protection rating | IP68 |
| Transmitter protection rating | IP65 |
| Sensor-to-transmitter cable | 4-core shielded cable with internal air/vent tube; default length 10 m, cable diameter 8 mm (other lengths customizable) |
| Operating temperature | 0 °C – 60 °C (non-freezing) |
| Storage temperature | –20 °C – 80 °C |
| Item | Code | Description |
|---|---|---|
| 01 Product series | DYFX | Split type, ABS housing |
| 02 Product type | FIDF | Doppler Ultrasonic Flow Meter |
| 03 Water level range | 03 / 10 / XX | 3 m range / 10 m range / other measuring range |
| 04 Sensor housing | A / F / P / S / T | ABS / PTFE / POM / Stainless steel / Other material |
| 05 Sensor mounting (thread) | AN | No thread |
| 06 Power type | DCSP / DC | 12 VDC / 24 VDC |
| 07 Output signal | MA / C2 / C4 / C2MA / C4MA | 4–20 mA / RS232 / RS485 / 4–20 mA + RS232 / 4–20 mA + RS485 |
| 08 Number of sensors | S1 | 1 sensor |
| 09 Transmitter housing material | PL | ABS |
| 10 Sensor cable length | 01 / ~ / 50 | 1 m / any length 1–50 m / 50 m |
Example: DYFX-FIDF-10-A-AN-DC-C4-S1-PL-10 = split ABS Doppler open-channel flow meter, 10 m level range, ABS sensor housing, 24 VDC, RS485 output, single sensor, 10 m cable.
The ultrasonic Doppler flow meter operates based on the Doppler effect. A probe emits a beam of ultrasonic waves at an upward (or forward) angle into the fluid, which contains impurities such as bubbles or particles (these impurities are assumed to move at the same velocity as the fluid flow).
When the ultrasonic waves strike these impurities, the reflected waves undergo a Doppler frequency shift (Δf); this shift is directly proportional to the flow velocity. By measuring the Doppler frequency shift (Δf), the flow velocity of the fluid can be determined.
Sino-Inst is a professional supplier of Doppler ultrasonic flow meters. Our meters come factory-preset with six channel algorithms, feature data retention of over 10 years during power outages, and utilize air-vented cables that remain fully functional at temperatures as low as -25°C. They are widely used for monitoring flow rates and water levels in rivers, open channels, and partially filled pipes.
In addition to Doppler ultrasonic flow meters, we offer a comprehensive range of other flow measurement solutions, including open-channel, positive displacement, and mass flow meters. Please feel free to contact our sales engineers to discuss the best flow measurement solution for your needs.
Zhang Wei, possesses 20 years of experience as an automation instrumentation engineer, specializing in the research, design, installation, commissioning, and maintenance of automation instruments.
Face to various instrument communication protocols (such as Modbus, Profibus, etc.), with solid hardware circuit design and software programming skills (proficient in C language and PLC programming). Has extensive project experience; projects he has led and participated in have all achieved outstanding results, improving product accuracy, reducing costs, and increasing production efficiency.
Possesses excellent communication and coordination skills and a strong team spirit, enabling him to quickly respond to customer needs and provide high-quality automation instrumentation solutions.
