Xylem YSI Pro20 Portable Dissolved Oxygen Meter
| Brand | Xylem |
|---|---|
| Origin | USA |
| Model | YSI Pro20 |
| Instrument Type | Portable |
| Measurement Principle | Polarographic & Galvanic (User-Selectable Sensor Types) |
| DO Range | 0–50 mg/L |
| Accuracy | ±2% of reading (0–20 mg/L) or ±0.2 mg/L, whichever is greater |
| Repeatability | ±2% |
| Detection Limit | 0.1 mg/L |
| Temperature Range | –5 to 55 °C |
| Temp Accuracy | ±0.3 °C |
| Barometric Pressure Range | 53–133 kPa |
| Pressure Accuracy | ±0.4 kPa (within ±15 °C of calibration temperature) |
| Salinity Compensation | 0–70 ppt (manual input, automatic compensation) |
| Data Storage | 50 datasets with timestamp |
| IP Rating | IP67 |
| Drop Test | 1-meter drop resistance |
| Certifications | RoHS, CE, WEEE |
| Warranty | 3 years (instrument), 2 years (cable), 1 year (polarographic sensor), 6 months (galvanic sensor) |
Overview
The Xylem YSI Pro20 Portable Dissolved Oxygen Meter is an engineered field-deployable instrument designed for high-reliability measurement of dissolved oxygen (DO) in aqueous environments using either polarographic or galvanic electrochemical sensing principles. It operates on the fundamental principle of oxygen diffusion through a selective membrane into an electrolyte-filled cell, where electrochemical reduction (polarographic) or spontaneous redox reaction (galvanic) generates a current proportional to dissolved O₂ concentration. The system integrates real-time barometric pressure compensation and manual salinity input to correct for environmental variables affecting oxygen solubility—critical for accurate reporting in estuarine, marine, freshwater, and wastewater applications. Its ruggedized architecture, including dual-compartment sealing and military-grade MS connectors, ensures operational integrity under demanding environmental conditions typical of regulatory monitoring, academic research, and industrial process control.
Key Features
- Field-serviceable design: User-replaceable sensors and cables enable rapid maintenance without return-to-factory servicing.
- Multi-sensor compatibility: Supports interchangeable polarographic and galvanic DO probes—ideal for varying deployment durations and power constraints; optional BOD probe with integrated stirrer available for laboratory biochemical oxygen demand testing.
- Sub-3-second one-button calibration: Automated air-saturation calibration with concurrent barometric pressure acquisition eliminates manual entry errors and reduces setup time.
- Rapid response kinetics: Achieves 95% of final reading in ≤8 seconds using standard membranes—among the fastest stabilization times documented for handheld electrochemical DO meters.
- IP67-rated enclosure with independent battery and electronics compartments: Maintains full functionality even if the battery chamber is submerged or compromised.
- Durability-engineered connectivity: MS-series waterproof quick-connectors rated for ≥300,000 mating cycles; stainless-steel sensor guard protects against impact and abrasion during immersion.
- Low-power operation: Dual AA alkaline batteries provide ≥400 hours of continuous use with low-battery indicator and auto-shutdown.
- Enhanced usability: Backlit LCD with luminous keypad enables operation in low-light field conditions; cable management kits support efficient handling of extended-length configurations (up to 100 m).
Sample Compatibility & Compliance
The YSI Pro20 is validated for use across natural and engineered water matrices—including rivers, lakes, coastal seawater, aquaculture systems, activated sludge basins, fermentation broths, and potable water distribution networks. It complies with international environmental monitoring frameworks requiring traceable, repeatable DO data, including EPA Method 360.1 (for Winkler comparison validation), ASTM D888 (Standard Test Methods for Dissolved Oxygen in Water), and ISO 5814:2012 (Water quality — Determination of dissolved oxygen — Electrochemical probe method). Its hardware and firmware architecture supports GLP-aligned workflows via timestamped data logging and user-accessible calibration history—though native 21 CFR Part 11 compliance requires external secure data export protocols.
Software & Data Management
The Pro20 stores up to 50 measurement records internally, each containing DO (mg/L and % saturation), temperature (°C), barometric pressure (kPa), salinity (ppt), date, and time. Data export is performed via manual transcription or optional infrared interface (YSI DataTrak software, sold separately), enabling integration into LIMS or spreadsheet-based QA/QC review. No onboard Bluetooth or Wi-Fi capability is included; however, the device’s standardized ASCII output format facilitates third-party script-driven ingestion. Calibration logs—including date, atmospheric pressure at time of calibration, and sensor type—are retained and viewable on-device to support audit readiness and method verification per ISO/IEC 17025 requirements.
Applications
- Regulatory field monitoring: Compliance sampling for NPDES permits, TMDL assessments, and ambient water quality surveys per USGS and state agency protocols.
- Aquatic ecosystem research: Diel DO profiling in wetlands, stratified reservoirs, and benthic boundary layers.
- Process optimization: Real-time aeration control in municipal wastewater treatment plants and dissolved oxygen setpoint validation in aerobic bioreactors.
- Academic instruction: Undergraduate and graduate lab exercises covering respiration kinetics, photosynthetic oxygen production, and sensor calibration theory.
- Industrial hygiene: Monitoring DO in recirculating cooling towers and food-grade process water loops where microbial growth risk correlates with oxygen availability.
- Emergency response: Rapid deployment during chemical spills or algal bloom events where hypoxic/anoxic conditions threaten aquatic life.
FAQ
What sensor technologies does the Pro20 support?
The Pro20 accepts both polarographic (requiring warm-up and polarization) and galvanic (self-powered, zero warm-up) DO sensors—selected by the user based on application duration, power availability, and required maintenance frequency.
Can the Pro20 measure DO in high-salinity seawater?
Yes—manual salinity input (0–70 ppt) triggers automatic solubility correction, ensuring accuracy across brackish to full-strength seawater (≈35 ppt) and hypersaline lagoons.
Is the instrument suitable for long-term unattended deployment?
No—the Pro20 is designed for spot-checking and short-duration profiling. For fixed-site monitoring, Xylem recommends the YSI EXO series or ProDSS platforms with telemetry and extended battery options.
How is barometric pressure measured and used?
An integrated pressure transducer acquires ambient pressure at calibration and measurement; this value is applied dynamically to convert raw current output into mg/L using the Benson-Krause solubility model.
What warranty coverage applies to consumable components?
Polarographic sensors are covered for 12 months; galvanic sensors for 6 months; cables for 24 months; and the main instrument housing for 36 months—valid from date of purchase with proof of origin.
