AnalogPlus™ Ozone Electrode by Thermo Fisher Scientific

Overview

The AnalogPlus™ Ozone Electrode is a precision amperometric (Clark-type) sensor engineered for continuous, real-time dissolved ozone monitoring in aqueous systems. Based on polarographic electrochemical detection, it operates via controlled-potential reduction of ozone at a gold cathode, with silver serving as both the anode and reference electrode. Unlike conventional two-electrode configurations, this three-electrode architecture applies a stable polarization voltage to the silver reference, minimizing drift and improving long-term signal stability—particularly critical in low-conductivity or variable-pH streams such as boiler feedwater or ultrapure rinse water. The sensor’s design adheres to fundamental principles of diffusion-limited current measurement, where the Faradayic current generated is directly proportional to the partial pressure of dissolved ozone diffusing through a selective gas-permeable membrane. This principle ensures high specificity, minimal cross-sensitivity to chlorine or hydrogen peroxide, and robust performance across dynamic industrial process environments.

Key Features

• Three-electrode Clark-type polarographic configuration with gold working electrode, silver counter electrode, and integrated silver reference electrode
• Pre-assembled, field-replaceable membrane cap assembly—no manual membrane stretching or electrolyte filling required
• Stable polarization voltage applied to silver reference electrode to suppress baseline drift and enhance measurement reproducibility
• Durable, chemically resistant housing rated for continuous immersion in potable water, wastewater, and aggressive disinfection streams
• Optimized membrane permeability and diffusion path geometry for rapid response (t₉₀ < 60 s) and consistent sensitivity across 0–10 ppm (0–10 mg/L) ozone range
• Resolution of 0.01 ppm enables precise control of low-dose ozone applications, including semiconductor wafer rinsing and pharmaceutical water system validation

Sample Compatibility & Compliance

The AnalogPlus Ozone Electrode is validated for use in drinking water distribution, municipal wastewater effluent, food-grade process water, pharmaceutical purified water (PW) and water-for-injection (WFI) loops, and cooling tower systems. It maintains accuracy across pH 4–9 and temperatures from 0 °C to 45 °C, with optional temperature compensation via integrated Pt1000 RTD. The sensor complies with ASTM D6756–22 (Standard Test Method for Determination of Dissolved Ozone in Water by Electrochemical Detection) and supports GLP/GMP data integrity requirements when paired with AV88 controllers featuring audit-trail-enabled firmware (21 CFR Part 11 compliant logging available). No calibration gases or certified ozone standards are required—two-point calibration using air-saturated water (zero) and a stable ozone-generating source (span) is sufficient for routine verification.

Software & Data Management

When interfaced with the Thermo Scientific AV88 Ozone Controller, the AnalogPlus electrode delivers analog 4–20 mA output with HART® protocol support, enabling integration into DCS, SCADA, and MES platforms. The AV88 firmware includes configurable alarm thresholds, automatic temperature compensation, and linearization algorithms optimized for ozone-specific diffusion kinetics. Raw sensor output is logged with timestamp, temperature, and diagnostic flags (e.g., membrane integrity warning, low electrolyte indicator). All calibration events, parameter changes, and system faults are recorded with user ID and ISO 8601 timestamps—fully traceable for FDA inspection readiness and internal quality audits.

Applications

• Real-time ozone dosing control in municipal drinking water treatment plants
• Monitoring residual ozone in bottled water ozonation tunnels and filler line rinse stations
• Validation of ozone-based sterilization cycles in pharmaceutical clean steam and PW systems
• Process optimization in pulp & paper bleaching stages requiring precise oxidant dosing
• Corrosion mitigation in closed-loop cooling water systems via controlled ozone residual maintenance
• In-line verification of ozone efficacy in semiconductor wet benches during photoresist stripping and particle removal

FAQ

What is the recommended calibration frequency for the AnalogPlus Ozone Electrode?

Calibration is recommended daily for critical GMP applications; weekly is acceptable for non-regulated industrial monitoring. A two-point (zero/span) procedure using air-saturated deionized water and a stable ozone generator output is standard.
Can the electrode be used in seawater or high-salinity brines?

No—it is not designed for conductivity > 2,000 µS/cm. High chloride concentrations accelerate silver electrode passivation and compromise reference stability.
Is the membrane cap assembly compatible with third-party controllers?

Yes—the electrode outputs a standardized 4–20 mA signal with passive load capability. However, full diagnostic functionality (e.g., membrane health alerts) requires AV88 firmware.
How often must the membrane cap be replaced?

Typical service life is 3–6 months under continuous operation in clean water; replacement frequency increases in turbid or organic-rich matrices due to membrane fouling.
Does the electrode require electrolyte refilling?

No—each pre-assembled membrane cap contains factory-sealed, long-life electrolyte gel; no user maintenance is required beyond cap replacement.