WTW Oxi 3310 Portable Dissolved Oxygen Meter

Overview

The WTW Oxi 3310 Portable Dissolved Oxygen Meter is an engineered field instrument designed for high-precision, trace-level dissolved oxygen (DO) quantification in aqueous environmental matrices. It operates on the galvanic cell electrochemical principle—utilizing a self-polarizing, membrane-covered sensor that generates a current proportional to the partial pressure of molecular oxygen diffusing across a gas-permeable membrane. This analog signal is converted into concentration (mg/L), saturation (%), or partial pressure (hPa) units with integrated temperature and barometric pressure compensation. The device meets the functional requirements of ISO 5814:2012 (water quality — determination of dissolved oxygen — electrochemical probe method) and supports compliance with EPA Method 360.1 and ASTM D888 for field-deployable DO analysis. Its robust architecture ensures stable operation under variable ambient conditions—from cold alpine streams to warm coastal estuaries—without requiring external power sources or laboratory infrastructure.

Key Features

• Galvanic cell probe technology with no external polarization voltage required—enabling immediate stabilization and reduced maintenance intervals
• High-resolution LCD with graphical backlit display for low-light field use and real-time trend visualization
• Intelligent calibration management: automatic buffer recognition (16 DIN/NIST standards), up to 5 stored calibration records, and on-screen electrode health diagnostics post-calibration
• Continuous Measurement Control (CMC) algorithm validates each reading against active calibration bounds; visual/audible alerts trigger when values fall outside validated ranges
• Dual-mode data acquisition: manual entry or time-triggered logging (configurable interval from 1 s to 24 h), supporting unattended long-term monitoring campaigns
• IP66/IP67-rated housing with silicone keypad—resistant to dust ingress, rain, splashing, and temporary submersion
• Integrated barometric pressure sensor enabling real-time atmospheric correction without manual input or external instrumentation
• USB interface with waterproof sealing—compatible with Windows-based PCs for secure, audit-ready data export using WTW LabX® Light software
• Extended battery endurance: up to 1000 hours on four AA alkaline cells; optional rechargeable NiMH configuration available

Sample Compatibility & Compliance

The Oxi 3310 is validated for use in natural waters (rivers, lakes, groundwater), wastewater effluents, aquaculture systems, and process water streams. It accommodates samples with turbidity ≤ 400 NTU and suspended solids ≤ 500 mg/L without membrane fouling under standard operating protocols. Electrode compatibility includes WTW CellOx® 325, DurOx® 325, and OxiCal® calibration tubes. The instrument conforms to IEC 61000-4 electromagnetic compatibility standards and carries CE marking per EU Directive 2014/30/EU (EMC) and 2014/35/EU (LVD). For regulated environments—including drinking water utilities operating under US EPA Safe Drinking Water Act (SDWA) or EU Drinking Water Directive (98/83/EC)—the Oxi 3310 supports GLP-compliant workflows via timestamped, non-editable data logs and user-accessible calibration history.

Software & Data Management

Data integrity is maintained through WTW’s proprietary LabX® Light software suite, which enables encrypted USB transfer, CSV/Excel export, and PDF report generation with embedded metadata (operator ID, location tag, calibration certificate ID, timestamp, sensor serial number). All logged entries include automatic annotation of temperature, pressure, and calibration status. Audit trail functionality complies with FDA 21 CFR Part 11 requirements when paired with configured user authentication and electronic signature modules. Raw data files are stored in WTW’s binary *.wtx format—readable only by certified LabX® applications—to prevent unauthorized modification. Firmware updates are delivered via signed firmware packages verified through SHA-256 checksum validation.

Applications

• Regulatory monitoring of surface water DO levels per national water quality standards (e.g., China’s GB 3838-2002, US EPA Region-specific criteria)
• Biochemical oxygen demand (BOD₅) incubation tracking in wastewater treatment plants
• Aquaculture pond management—optimizing aeration cycles based on diurnal DO fluctuations
• Environmental impact assessments (EIA) for hydroelectric dam operations and dredging projects
• Field validation of online DO sensors installed in municipal water distribution networks
• Research-grade profiling in limnological and marine studies, including benthic zone characterization

FAQ

What calibration standards are supported?
The Oxi 3310 automatically recognizes 16 standardized buffer solutions per DIN 19266 and NIST traceable specifications—including air-saturated water, zero-oxygen sodium sulfite solution, and custom-defined standards.
Can the instrument be used for deep-water profiling?
While the Oxi 3310 itself is rated IP67, it is not designed for direct submersion beyond 1 m. For depths up to 100 m, WTW recommends pairing the Oxi 197i system with TA197 submersible probe assembly, which features stainless-steel housing and 10-bar pressure rating.
Is temperature compensation fully automated?
Yes—integrated Pt1000 RTD sensor provides continuous ATC across the full operational range (–5.0 to 105.0 °C), with accuracy of ±0.1 °C.
How is data security ensured during transfer?
USB communication employs hardware-level encryption; exported files retain digital signatures verifying origin, integrity, and temporal sequence—meeting ISO/IEC 17025 clause 7.5.2 requirements for data authenticity.
Does the device support multi-parameter expansion?
The Oxi 3310 is a dedicated DO platform. For combined pH/conductivity/DO measurements, WTW’s Multi 3630 or IQ Sensor Net platforms are recommended as modular alternatives.