WTW SensoLyt PL pH/ORP Online Sensor

Overview

The WTW SensoLyt PL is a high-integrity, digital pH/ORP online sensor engineered for continuous, stable measurement in demanding water and wastewater monitoring applications. It operates on the fundamental electrochemical principle of potentiometric sensing: a pH-sensitive glass membrane generates a potential difference proportional to hydrogen ion activity in solution, while an integrated Ag/AgCl reference system—stabilized by a gel or solid polymer electrolyte—provides a reproducible, low-drift reference potential. Unlike conventional liquid-filled electrodes, the SensoLyt PL eliminates electrolyte leakage, concentration drift, and clogging risks through its sealed, maintenance-free reference architecture. Its IQ digital interface enables plug-and-play integration with WTW’s 2020, 28X, and IQ SENSOR NET platforms, supporting automatic sensor identification, firmware updates, and embedded calibration history.

Key Features

• Digital IQ interface with onboard EEPROM: stores calibration parameters, sensor ID, service history, and diagnostic logs—enabling traceability and reducing manual configuration errors.
• Modular dual-parameter design: single housing accommodates both pH and ORP sensing elements, minimizing installation footprint and streamlining maintenance.
• Gel- and polymer-based reference systems: ensure long-term stability in variable ionic strength environments—including seawater (SW variants), industrial effluents, and biologically active wastewaters—without refilling or reconditioning.
• Robust mechanical construction: stainless steel 316L or titanium/POM body rated IP68 and pressure-resistant up to 12 bar (model-dependent), suitable for submersible, inline, and insertion-style installations.
• Integrated temperature compensation: built-in NTC thermistor (−5 to +60 °C); optional Pt1000 or Pt100 support for extended-range or regulatory-grade applications.
• Self-diagnostics capability: real-time monitoring of glass membrane integrity, reference junction status, and signal noise—triggering alerts for electrode damage or contamination before measurement drift occurs.

Sample Compatibility & Compliance

The SensoLyt PL series is validated for use across heterogeneous aqueous matrices, including municipal wastewater, surface water, drinking water (DWA variant), seawater and brackish effluents (SW variant), and high-fouling streams containing suspended solids, proteins, sulfides, or emulsifiers (SEA/SEA-HP variants). Its polymer-reference design inherently resists poisoning from AgCl precipitation, heavy metals, and reducing agents—critical for compliance with ISO 10523 (water quality — determination of pH), ASTM D1293 (Standard Test Method for pH of Water), and EN ISO 5667-3 (water quality sampling — guidance on preservation and handling). When deployed in IQ SENSOR NET systems, data acquisition meets GLP/GMP audit-trail requirements per FDA 21 CFR Part 11 when paired with compliant host controllers and software.

Software & Data Management

All SensoLyt PL sensors communicate via WTW’s proprietary IQ protocol over RS-485 or M-Bus, enabling seamless interoperability with the IQ SENSOR NET controller family (e.g., IQ SENSOR NET 2020, 28X). Host systems automatically recognize sensor type, firmware version, and calibration status. Calibration data—including date, buffer values, slope, and offset—is stored directly on the sensor and synchronized during each communication cycle. WTW’s LabX® and MultiLine® software packages support automated report generation, trend analysis, alarm threshold configuration, and export to CSV or XML formats compatible with LIMS and SCADA systems. Firmware updates are performed remotely without physical sensor removal.

Applications

• Continuous pH/ORP monitoring in primary and secondary wastewater treatment processes (e.g., equalization tanks, anoxic zones, disinfection basins).
• Seawater desalination pre-treatment and post-treatment control, where chloride interference and biofouling resistance are critical.
• Industrial process water loops—especially in food & beverage, pharmaceutical, and chemical manufacturing—requiring rapid response, low maintenance, and regulatory-compliant documentation.
• Drinking water distribution networks, where DWA-configured units ensure compliance with WHO and EU Drinking Water Directive (98/83/EC) pH specifications.
• High-temperature/pressure applications (via CHEMtrac 830 M integration), such as steam condensate return lines or sterilization effluent streams.

FAQ

Does the SensoLyt PL require electrolyte refilling or routine maintenance?

No—its gel or solid polymer reference system is permanently sealed and designed for maintenance-free operation over its full service life.
Can the pH and ORP elements be replaced independently?

Yes—the modular design allows individual replacement of the pH glass sensor or ORP sensing element without replacing the entire probe assembly.
Is temperature compensation automatic and configurable?

Yes—integrated NTC provides default compensation; Pt1000/Pt100 options support higher-accuracy applications and regulatory validation protocols.
How is calibration data retained during power loss or sensor disconnection?

Calibration metadata is stored in non-volatile memory on the sensor itself, persisting across power cycles and field replacements.
What certifications apply to the SensoLyt PL for hazardous area installations?

The standard SensoLyt PL carries CE, RoHS, and IP68 certification; ATEX or IECEx variants are available upon request for Zone 1/21 deployments.