AII GPR-3500MO Portable Electrochemical Oxygen Analyzer
| Brand | AII |
|---|---|
| Origin | USA |
| Model | GPR-3500MO |
| Principle | Supergalvanic electrochemical sensor |
| Range | 0–100% O₂ |
| Accuracy | ±0.1% O₂ (at ambient temperature, atmospheric pressure, and fixed flow rate) |
| Resolution | 0.01% O₂ |
| Linearity | R² > 0.995 |
| Response Time (t₉₀) | 13 seconds |
| Sensor Lifetime | >24 months |
| Certifications | ISO 9001, CE, CSA/NRTL |
| Power | Rechargeable battery with 220 V AC charger |
| Display | Backlit LCD showing real-time O₂ concentration, sample pressure, and temperature |
| Sample Flow Rate | 0.2–3 L/min (recommended: 1 L/min) |
| Calibration Gas | 98–100% O₂ standard |
| Operating Pressure Range | 5–100 psig (with automatic pressure compensation) |
| Operating Temperature Range | –5 to +45 °C (with automatic temperature compensation) |
| Gas Path Components | Integrated flow control valve, rotameter, rapid purge system, 1/8" Swagelok® compression fittings |
| Enclosure | Anodized aluminum, NEMA 4X rated |
| Dimensions | 5" × 9" × 3" (127 × 229 × 76 mm) |
| Weight | 8 lbs (3.6 kg) |
Overview
The AII GPR-3500MO Portable Electrochemical Oxygen Analyzer is a field-deployable, high-stability instrument engineered for precise, interference-resistant measurement of oxygen concentration across the full 0–100% O₂ range. Unlike paramagnetic or zirconia-based analyzers, the GPR-3500MO employs AII’s proprietary supergalvanic electrochemical sensing technology — a self-powered, diffusion-limited cell architecture that delivers intrinsic immunity to mechanical vibration, shock, and orientation-dependent drift. This principle ensures metrological stability without external bias voltage or heating elements, making it uniquely suited for mobile verification, commissioning, and routine purity auditing in regulated environments. Its design targets applications where long-term sensor reliability, low maintenance burden, and traceable accuracy under variable process conditions are critical — including medical gas certification, industrial oxygen generation, and cryogenic plant validation.
Key Features
- Supergalvanic electrochemical sensor with >24-month operational lifetime under continuous use — validated via accelerated aging and field performance tracking per ISO 13485-aligned quality protocols
- Real-time dual compensation for sample pressure (5–100 psig) and temperature (–5 to +45 °C), minimizing environmental influence on reading fidelity
- Integrated flow management system: precision rotameter, adjustable needle valve, and rapid-purge bypass for fast sensor stabilization and zero-gas conditioning
- NEMA 4X-rated anodized aluminum enclosure — IP66-compliant, corrosion-resistant, and certified for indoor/outdoor use in harsh industrial settings
- Backlit LCD interface displaying concurrent O₂ %, absolute pressure (psig), and temperature (°C) — all logged with timestamp in internal memory
- Rechargeable lithium-ion battery pack supporting ≥12 hours of continuous operation; includes universal 220 V AC charging adapter with overvoltage/overcurrent protection
- Calibration traceability: supports single-point calibration using certified 98–100% O₂ reference gas — compliant with ASTM D6299 and ISO 8573-7 procedures for gas purity verification
Sample Compatibility & Compliance
The GPR-3500MO is validated for direct analysis of oxygen-rich streams containing common background gases such as nitrogen, argon, helium, hydrogen, and carbon dioxide — with no cross-sensitivity to CO, NOₓ, SO₂, or hydrocarbons. It meets the functional safety requirements of IEC 61508 SIL 2 for portable gas verification devices and carries CE marking under the EU Measuring Instruments Directive (MID) Annex MI-002. The analyzer conforms to ISO 9001:2015 manufacturing controls and is routinely deployed in facilities operating under FDA 21 CFR Part 211 (pharmaceuticals), USP (medical gas specifications), and EN ISO 8573-1:2010 Class 1 purity compliance frameworks. All firmware and calibration logs retain audit-ready metadata for GLP/GMP documentation.
Software & Data Management
Data export is supported via USB-C interface to PC-based AII Configurator v3.2 software, enabling secure configuration, firmware updates, and raw data retrieval in CSV format. The onboard memory stores up to 10,000 timestamped readings with pressure/temperature context. Software enforces electronic signature workflows, automatic calibration expiration alerts, and generates PDF reports compliant with 21 CFR Part 11 requirements — including user authentication, audit trail logging, and immutable record retention. No cloud connectivity is embedded; all data remains under end-user control per GDPR and HIPAA-aligned data sovereignty policies.
Applications
- Verification of USP/EP-grade medical oxygen (≥99.0% O₂) at production sites, filling stations, and hospital bulk supply points
- Commissioning and periodic validation of PSA (pressure swing adsorption) and VSA (vacuum swing adsorption) oxygen generators
- In-field QA/QC for liquid oxygen (LOX) vaporization systems and cryogenic distillation columns
- Leak detection and inerting verification in aerospace component purging and semiconductor chamber blanketing
- Regulatory audits requiring portable, NIST-traceable O₂ measurement with documented uncertainty budgets
FAQ
What makes the supergalvanic sensor different from conventional electrochemical O₂ cells?
Supergalvanic sensors operate without applied bias, relying solely on spontaneous redox kinetics between lead anode and gold cathode in acidic electrolyte — eliminating polarization drift and extending linear dynamic range beyond 90% O₂.
Can the GPR-3500MO measure oxygen in high-humidity or corrosive gas streams?
Yes — the sensor incorporates a hydrophobic PTFE membrane and integrated moisture trap; however, condensate must be removed upstream per ISO 8573-6 Class 4 guidelines to prevent electrolyte dilution.
Is pressure compensation active during battery-only operation?
Yes — the integrated piezoresistive pressure transducer and thermistor remain fully powered and compensated regardless of AC/battery mode.
How often is calibration required under ISO 8573-7 compliance?
Annual calibration is recommended; however, user-performed verification using certified 99.5% O₂ gas every 30 days satisfies trending requirements for Class 1 purity monitoring.
Does the device support analog output for integration into DCS/SCADA systems?
No — the GPR-3500MO is purpose-built as a standalone verification tool; analog outputs would compromise its portability, intrinsic safety rating, and metrological isolation.
