GreenPrima PROLEV500 Split-Type Ultrasonic Level Meter

Overview

The GreenPrima PROLEV500 is a split-type ultrasonic level meter engineered for high-reliability non-contact level measurement in demanding industrial environments. Based on time-of-flight (ToF) ultrasonic principle, the instrument transmits high-frequency acoustic pulses from a remotely mounted sensor toward the surface of the measured medium; the elapsed time between pulse emission and echo return is precisely calculated to determine distance, which is then converted into level or volume data. Unlike contact-based technologies, this method eliminates mechanical wear, corrosion risks, and process contamination—making it ideal for aggressive liquids (e.g., acids, caustics), slurries, granular solids, and viscous media. The system’s modular architecture separates the ultrasonic transducer (PSU06 or PSU12) from the intelligent controller unit, enabling flexible installation in high-temperature, high-humidity, or electrically noisy locations where integrated units would be compromised.

Key Features

• True split architecture: Sensor and controller are physically decoupled via shielded 10 m cable (standard), allowing optimal placement of each component per site constraints—e.g., sensor in hazardous zones (IP68-rated), controller in accessible control cabinets (IP66).
• Adaptive signal processing: Real-time microprocessor-driven algorithms perform automatic gain control, dynamic power adjustment, and built-in temperature compensation (using integrated Pt1000 sensor in probe housing) to maintain accuracy across ambient fluctuations.
• Advanced echo discrimination: Proprietary waveform analysis filters out false echoes caused by tank obstructions, agitators, foam, or vapor layers—ensuring stable readings even in turbulent or multi-reflection scenarios.
• Dual analog outputs (4–20 mA) configurable for level, distance, or derived volume—with independent zero/span and damping settings per channel.
• Modbus RTU (RS-485) interface compliant with Modbus Application Protocol v1.1, supporting up to 247 slave addresses for seamless integration into DCS, SCADA, or PLC systems without protocol gateways.
• Configurable relay logic: PROLEV500 offers two programmable SPDT relays; PROLEV500D expands to five—each assignable to level alarms, pump control, overflow prevention, or batch sequencing per IEC 61508 SIL 1 functional safety guidelines.

Sample Compatibility & Compliance

The PROLEV500 is validated for continuous level monitoring of both liquids and bulk solids—including wastewater, potable water, chemical reagents (HCl, NaOH), food-grade syrups, grain silos, and fly ash hoppers. Its ETFE- or PVDF-coated transducer diaphragms resist hydrolysis, UV degradation, and chemical attack per ISO 15142-1. The controller meets EMC Directive 2014/30/EU (EN 61326-1:2013) and Low Voltage Directive 2014/35/EU (EN 61000-6-2/6-3). All firmware and configuration logs support audit trails required under FDA 21 CFR Part 11 when deployed in regulated pharmaceutical or food manufacturing facilities operating under cGMP or HACCP frameworks.

Software & Data Management

Configuration and diagnostics are performed locally via the 320 × 240 color LCD with intuitive menu navigation—or remotely using GreenPrima’s free PC-based LevelConfig software (Windows 10/11 compatible). The software enables full parameter cloning, firmware updates, real-time waveform visualization, echo profile logging, and CSV export of historical level trends. All configuration changes are timestamped and user-logged; critical parameters (e.g., measurement range, damping factor, relay thresholds) are protected by multi-level password access. Data integrity is preserved through cyclic redundancy check (CRC) on all Modbus frames and non-volatile memory retention (>10 years) for calibration constants and event history.

Applications

• Municipal water & wastewater: Open-channel flow measurement (with Parshall/ Palmer-Bowlus flumes), wet well level control, clarifier sludge blanket monitoring.
• Chemical processing: Storage tank inventory management, reactor fill-level supervision, drum-level verification in filling lines.
• Food & beverage: CIP tank level validation, syrup blending vessel control, grain silo inventory tracking with dust explosion mitigation (ATEX-compliant mounting kits available).
• Power generation: Ash hopper level detection, condensate tank monitoring, cooling tower basin control.
• Environmental monitoring: Rainwater harvesting tanks, leachate sumps in landfill sites, remote reservoir telemetry (when paired with GSM/GPRS data loggers).

FAQ

What is the maximum allowable distance between sensor and controller?
The standard shielded cable length is 10 m. Extended lengths up to 30 m are supported with appropriate cable specification (twisted-pair, foil-braided shield, ≤100 pF/m capacitance) and voltage drop verification per IEC 60204-1.

Can the PROLEV500 measure through foam or heavy vapor?
Yes—the adaptive echo processing and multi-echo rejection algorithm distinguish true surface returns from attenuated or scattered signals, though extreme foam (>5 cm thickness, low-density) may require empirical calibration or alternative sensing methods.

Is ATEX or IECEx certification available?
The base PROLEV500 is not intrinsically safe certified; however, explosion-proof enclosures (Ex d IIB T4) and associated Zener barriers are offered as optional accessories for Zone 1/2 installations.

How is temperature compensation implemented?
A Pt1000 resistance thermometer embedded in the sensor housing continuously measures local transducer temperature. The controller applies real-time speed-of-sound correction using the standard ultrasonic velocity equation for air (v = 331.4 + 0.6T m/s), referenced to the measured temperature.

Does the device support HART communication?
No—HART is not supported. Communication is limited to Modbus RTU over RS-485 and analog 4–20 mA outputs. HART-capable variants are not part of the PROLEV500 product line.