GreenPrima PM820 2C Online Conductivity Analyzer

Overview

The GreenPrima PM820 2C Online Conductivity Analyzer is a precision-engineered industrial process instrument designed for continuous, real-time measurement of electrical conductivity, salinity, and total dissolved solids (TDS) in liquid streams across water treatment, chemical processing, pharmaceutical manufacturing, food & beverage production, and power generation applications. It operates on the principle of two-electrode or four-electrode conductometric measurement—where an alternating current is applied across a sensor cell, and the resulting voltage drop is used to calculate solution conductivity based on cell constant calibration. The analyzer features automatic temperature compensation (ATC) using either NTC30k or PT1000 sensors, ensuring metrological traceability across a wide thermal operating envelope (−10 to +70 °C). Its dual-range capability—from ultra-low conductivity (µS/cm) up to high-conductivity brines (2000 mS/cm)—enables deployment in diverse media, including ultrapure water, cooling tower blowdown, seawater desalination feed, and caustic cleaning solutions.

Key Features

• True dual-channel configuration supporting simultaneous conductivity and temperature measurement with independent signal conditioning
• Backlit high-contrast dot-matrix LCD display with intuitive icon-driven interface and selectable English/Chinese language support
• Dual isolated 4–20 mA analog outputs—fully configurable for conductivity, salinity, TDS, or temperature; each with 0.1% full-scale accuracy and loop resistance up to 500 Ω
• RS485 serial interface compliant with Modbus RTU protocol for seamless integration into DCS, SCADA, and PLC-based control systems
• Two programmable relay outputs (5 A / 250 VAC / 30 VDC) with adjustable hysteresis for process alarms, pump control, or valve actuation
• Configurable cleaning cycle output—interval (0.1–1000 h) and duration (1–1000 s) independently set to automate electrode maintenance in fouling-prone environments
• Factory-reset function accessible via dedicated hardware key, preserving configuration integrity during field servicing
• Flexible mechanical mounting options: wall-mount, panel-mount (138 × 138 mm cutout), and inline pipe-mount configurations
• Robust IP65-rated enclosure constructed from UV-stabilized polycarbonate and stainless steel fasteners for long-term reliability in harsh industrial environments

Sample Compatibility & Compliance

The PM820 2C is compatible with a broad spectrum of aqueous process streams—including deionized water, boiler feedwater, reverse osmosis permeate, municipal wastewater effluent, and aggressive chemical solutions—when paired with appropriate electrode materials (e.g., graphite, stainless steel 316L, or titanium). Sensor selection is critical for optimal performance: two-electrode cells are recommended for low-to-moderate conductivity (0.01–20 mS/cm), while four-electrode (inductive) sensors eliminate polarization errors and enable stable measurement in high-conductivity, high-fouling media (>100 mS/cm). The analyzer complies with IEC 61000-6-2 (immunity) and IEC 61000-6-4 (emissions) for industrial electromagnetic compatibility. While not intrinsically safe certified, it meets EN 61010-1 safety requirements for measurement/control equipment. Data logging (600,000 records) supports GLP/GMP-aligned audit trails when integrated with time-stamped SCADA historians.

Software & Data Management

Configuration and diagnostics are performed locally via the front-panel keypad or remotely via Modbus register mapping. The embedded firmware supports linear and non-linear temperature compensation algorithms per ASTM D1125 and ISO 7888 standards. All parameter changes—including calibration coefficients, alarm thresholds, and output scaling—are logged with timestamp and user ID (if password-protected access is enabled). Optional HART communication module (available upon request) enables FDI device description integration and advanced diagnostics in legacy analog infrastructure. Data export is supported through periodic polling or event-triggered transmission; no proprietary software is required for basic commissioning or routine maintenance.

Applications

• Continuous monitoring of conductivity in demineralized water loops for steam generation and turbine condensate return systems
• Real-time salinity control in aquaculture recirculating systems and marine hatcheries
• TDS verification in RO/NF membrane system performance audits and reject stream management
• Concentration tracking of sodium hydroxide, sulfuric acid, or sodium chloride solutions in CIP (clean-in-place) skids
• Effluent compliance monitoring against local discharge limits (e.g., EPA 40 CFR Part 403, EU Urban Wastewater Directive)
• Process validation support for pharmaceutical water systems per USP and EP 2.2.38

FAQ

What electrode types are compatible with the PM820 2C?
The analyzer supports both contacting (two- and four-electrode) and inductive (toroidal) conductivity sensors via standardized BNC or M12 connectors. Electrode material selection must match chemical compatibility requirements—consult GreenPrima’s sensor compatibility matrix prior to installation.
Does the unit support automatic temperature compensation?
Yes. ATC is implemented using either NTC30k thermistors or PT1000 RTDs, with compensation ranges spanning −10 to +130 °C. Manual temperature offset adjustment is also available for fine-tuning in non-uniform thermal gradients.
Can the PM820 2C be integrated into a Siemens S7 PLC network?
Absolutely. Native Modbus RTU over RS485 ensures plug-and-play interoperability with Siemens SIMATIC S7-1200/1500 controllers using standard MB_CLIENT/MB_SERVER blocks.
Is calibration traceable to national standards?
Field calibration is performed using certified KCl standard solutions (e.g., 1413 µS/cm, 12.88 mS/cm). Calibration certificates issued by accredited labs (UKAS or equivalent) are available upon request for GxP-regulated installations.
What is the maximum data retention capacity?
The internal flash memory stores up to 600,000 timestamped measurement records (conductivity, temperature, TDS, salinity), with configurable logging intervals from 1 second to 24 hours.