GreenPrima PROLEV600 Ultrasonic Open-Channel Flowmeter

Overview

The GreenPrima PROLEV600 Ultrasonic Open-Channel Flowmeter is an engineered solution for continuous, non-intrusive flow measurement in partially filled conduits—commonly referred to as open channels. Unlike submerged or inline flowmeters, the PROLEV600 operates on the principle of ultrasonic time-of-flight (ToF) level sensing: it emits high-frequency acoustic pulses toward the water surface and precisely measures the return echo time to calculate liquid level height. This level data is then combined with pre-configured hydraulic geometry (e.g., Parshall, Palmer-Bowlus, or Palmer-Bowlus-type flumes; Palmer-Bowlus, Palmer-Bowlus, or custom trapezoidal weirs) to compute instantaneous volumetric flow rate using established open-channel hydraulics equations (e.g., ISO 1438, ASTM D1941, and ISO 4359). By eliminating mechanical contact with the fluid, the system avoids fouling, corrosion, and drift associated with submersible sensors—and critically, mitigates errors caused by air temperature gradients and humidity-induced sound velocity variations that commonly degrade conventional ultrasonic or radar-based level instruments.

Key Features

• Non-contact ultrasonic level measurement ensures long-term stability in aggressive wastewater, saline effluent, or chemically contaminated environments
• High-resolution level detection (1 mm) with a narrow blind zone (0.25 m), enabling accurate low-flow measurement even in shallow or variable-depth channels
• Thermally compensated transducer design minimizes drift across ambient operating temperatures from –30 °C to +70 °C
• Integrated dual-output capability: isolated 4–20 mA analog signal for PLC/SCADA integration and RS485 serial interface compliant with Modbus RTU for bidirectional configuration and diagnostics
• Backlit monochrome LCD display with intuitive membrane keypad supports local setup, real-time parameter review (instantaneous flow, accumulated volume, average flow over user-defined intervals), and alarm status indication
• Ruggedized housing constructed from UV-stabilized PC/PP composite material, rated IP67 for full dust ingress protection and temporary immersion resistance
• Configurable support for standardized and non-standard hydraulic structures—including Parshall, Palmer-Bowlus, Palmer-Bowlus, Trapezoidal, and Cipoletti weirs—as well as user-defined stage-discharge tables

Sample Compatibility & Compliance

The PROLEV600 is validated for use with turbulent, aerated, or suspended-solids-laden flows typical in municipal wastewater treatment plants, industrial discharge monitoring points, irrigation canals, stormwater overflows, and combined sewer systems. Its non-contact operation eliminates sensitivity to turbidity, oil sheen, foam, or biological growth—factors that impair optical or capacitive level sensors. The device complies with electromagnetic compatibility (EMC) requirements per EN 61326-1:2013 and meets functional safety recommendations for Level 1 instrumentation per IEC 61508. While not intrinsically safe, its 24 VDC power architecture enables deployment in Zone 2 hazardous areas when installed with appropriate barrier systems. Calibration traceability follows UKAS-accredited procedures aligned with ISO/IEC 17025, and documentation supports regulatory reporting under EPA Method 1605, EU WFD (Water Framework Directive) Annex V, and ISO 5555–5557 for open-channel flow measurement.

Software & Data Management

Configuration and commissioning are performed via the GreenPrima Configuration Utility—a Windows-based desktop application that connects via USB-to-RS485 adapter. The utility enables full parameterization of hydraulic geometry, unit selection (m³/h, L/s, gal/min), averaging windows (1–3600 s), alarm thresholds (high/low level, flow deviation), and data logging intervals. All configuration changes are timestamped and stored in non-volatile memory with built-in audit trail functionality. The Modbus RTU register map includes read-only access to diagnostic registers (e.g., signal strength, temperature compensation offset, echo quality index), supporting predictive maintenance planning. For enterprise-level integration, GreenPrima provides OPC UA companion specification documentation compatible with leading SCADA platforms (e.g., Siemens Desigo, Schneider EcoStruxure, Rockwell FactoryTalk).

Applications

• Municipal wastewater treatment: influent and effluent flow monitoring at headworks, secondary clarifiers, and disinfection outfalls
• Industrial compliance monitoring: continuous discharge verification at regulated outfall points per ISO 14001 and local environmental permits
• Drinking water distribution: raw water intake and treated water delivery verification in gravity-fed channels
• Agricultural water management: real-time allocation tracking across gated irrigation canals and lateral ditches
• Urban drainage infrastructure: combined sewer overflow (CSO) event quantification and flood forecasting model input
• Research and education: hydrological field studies requiring portable, low-maintenance flow instrumentation

FAQ

Does the PROLEV600 require regular recalibration?
No—its ultrasonic transducer is factory-calibrated with NIST-traceable reference standards and maintains calibration stability for ≥24 months under normal operating conditions. Field verification may be performed using a certified ultrasonic distance calibrator or physical staff gauge comparison.

Can the PROLEV600 operate reliably in outdoor installations with direct sunlight exposure?
Yes—the PC/PP housing incorporates UV stabilizers and thermal mass design to limit internal temperature rise; operational integrity is maintained up to +70 °C ambient, and the LCD remains legible under full solar irradiance.

Is Modbus TCP supported?
No—only Modbus RTU over RS485 is implemented. For TCP/IP integration, a protocol gateway (e.g., Moxa EDS-G205A) is recommended.

What is the minimum measurable flow velocity in a 1 m wide Parshall flume?
The lower limit depends on channel geometry and installation height, but with optimal mounting (≥0.5 m above maximum expected water level), the system reliably resolves flows corresponding to ≤2 mm level change—equivalent to ~0.05 L/s in standard Parshall configurations.