GreenPrima PM820 2P Online pH/ORP Analyzer with Temperature Compensation

Overview

The GreenPrima PM820 2P Online pH/ORP Analyzer is an industrial-grade electrochemical process analyzer engineered for continuous, real-time monitoring of hydrogen ion activity (pH) and redox potential (ORP) in demanding aqueous environments. Built upon potentiometric measurement principles, the instrument interfaces with glass pH electrodes and noble-metal ORP electrodes—measuring the voltage difference between a sensing electrode and a stable reference electrode under Nernstian equilibrium conditions. Its dual-channel capability supports simultaneous pH and ORP quantification, with integrated Pt1000-based temperature sensing enabling automatic, traceable temperature compensation per ISO 17025-compliant calibration protocols. Designed specifically for integration into distributed control systems (DCS) and programmable logic controllers (PLC), the PM820 2P operates across municipal wastewater treatment plants, chemical process streams, cooling tower circuits, and surface water quality monitoring stations—where long-term stability, electrical noise immunity, and regulatory traceability are non-negotiable.

Key Features

• Rugged IP65-rated enclosure with reinforced polycarbonate housing, rated for continuous operation in high-humidity, chemically aggressive, and EMI-prone industrial zones.
• Backlit dot-matrix LCD display delivering simultaneous, high-contrast visualization of pH, ORP, and temperature values—optimized for low-light or outdoor panel-mount installations.
• Dual isolated 4–20 mA analog outputs, each independently configurable for pH, ORP, or temperature signals, with maximum loop impedance of 600 Ω—fully compliant with IEC 61000-6-2/6-4 EMC standards.
• Two fully programmable relay outputs (230 VAC, 5 A resistive load), supporting fail-safe alarm logic, pump interlocks, or dosing system activation based on user-defined Hi/Lo thresholds.
• Auto-calibration functionality supporting up to five NIST-traceable buffer options (1.68, 4.01, 6.86, 9.18, 12.45 pH), with slope and offset validation logged internally for audit-ready GLP/GMP compliance.
• Factory-reset capability ensures reproducible configuration recovery without firmware reflash—critical for validated environments governed by FDA 21 CFR Part 11 and EU Annex 11 requirements.

Sample Compatibility & Compliance

The PM820 2P is compatible with standard double-junction pH electrodes (e.g., Ag/AgCl reference systems with gel-filled or refillable electrolytes) and platinum or gold ORP electrodes conforming to ASTM D1293 and ISO 10523 specifications. It accommodates both flowing and static sample configurations, including immersion, flow-cell, and bypass-loop installations. The analyzer meets CE marking requirements under the Low Voltage Directive (2014/35/EU) and Electromagnetic Compatibility Directive (2014/30/EU). Its analog output architecture supports SIL 2 functional safety integrity per IEC 61508 when deployed with certified field devices and proper system-level validation.

Software & Data Management

While the PM820 2P operates as a standalone, microprocessor-controlled analyzer without embedded PC software, its parameter set—including calibration history, relay event timestamps, and analog output scaling—is stored in non-volatile memory with battery-backed retention. All configuration changes generate internal audit trails with date/time stamps—enabling full traceability for laboratories operating under ISO/IEC 17025 or pharmaceutical QA/QC frameworks. Optional HART-enabled versions (PM820 2P-H) support digital diagnostics and remote parameter adjustment via standard 4–20 mA HART communication, facilitating integration with DeltaV, Emerson DeltaV, or Siemens Desigo CC platforms.

Applications

• Municipal and industrial wastewater treatment: real-time pH control during neutralization, coagulation, and biological nutrient removal stages.
• Chemical manufacturing: inline monitoring of acid/base addition in batch reactors and continuous stirred-tank reactors (CSTRs).
• Power plant cooling water systems: corrosion mitigation via ORP-guided biocide dosing and pH stabilization.
• Food & beverage processing: verification of CIP rinse efficacy and sanitization endpoint detection.
• Environmental monitoring networks: autonomous river and reservoir stations requiring low-maintenance, wide-range pH/ORP logging under unattended conditions.

FAQ

Does the PM820 2P support automatic temperature compensation using external Pt1000 sensors?
Yes—the device accepts direct Pt1000 input for fully automatic, linearized temperature compensation per DIN EN 60751, eliminating manual offset entry errors.
Can the two 4–20 mA outputs be assigned to different parameters simultaneously?
Yes—Output 1 may be configured for pH while Output 2 is assigned to ORP or temperature, with independent zero/span and damping settings.
Is the relay output suitable for direct motor or solenoid valve control?
Each relay contact is rated for 230 VAC at 5 A resistive load; inductive loads require external suppression diodes or solid-state relays per IEC 60947-5-1.
What calibration buffers are supported for two-point pH calibration?
The unit supports seven standard buffers (1.68, 4.01, 6.86, 7.00, 9.18, 10.01, 12.45 pH); users select any two for slope and offset calculation.
How is data integrity ensured during power interruption?
All configuration parameters, calibration records, and relay event logs are retained in EEPROM with >10-year data retention—no volatile RAM dependency.