Servomex MonoExact DF-310E Digital Trace Oxygen Analyzer

Overview

The Servomex MonoExact DF-310E is a high-stability digital trace oxygen analyzer engineered for continuous, low-level oxygen measurement in ultra-pure and industrial gas streams. It employs a precision paramagnetic sensing principle—based on the strong magnetic susceptibility of molecular oxygen—to deliver inherently selective, drift-free detection without consumables or catalytic surfaces. Unlike electrochemical or zirconia-based sensors, the paramagnetic cell exhibits no cross-sensitivity to CO₂, H₂, CO, or hydrocarbons, making it ideal for demanding applications such as bulk nitrogen generation, argon blanketing, hydrogen purification, and electronic-grade specialty gas certification. The DF-310E operates across four user-selectable concentration ranges (0–100 ppm high-resolution, 0–100 ppm, 0–1,000 ppm, and 0–10,000 ppm), with full-scale accuracy maintained via factory calibration traceable to NIST-certified standards. Its robust architecture supports continuous operation under varying pressure (up to 10 bar abs) and temperature (–20 °C to +50 °C ambient), with inlet gas conditioning integrated into the standard flow path.

Key Features

• True paramagnetic oxygen detection—no sensor poisoning, zero electrolyte maintenance, and <1% FS long-term drift per year
• High-resolution 0–100 ppm range optimized for purity verification in semiconductor-grade gases (e.g., N₂, Ar, He, H₂)
• Backward compatibility with legacy DF-310E hardware interfaces—including terminal blocks for discrete I/O, pneumatic gas inlets, and mounting footprints
• Multi-protocol digital communication suite: native support for Modbus TCP/IP (Ethernet), Profibus DP, RS232, and RS485 for seamless integration into DCS, PLC, and SCADA systems
• Configurable 4–20 mA analog output with HART 7.5 capability for loop-powered diagnostics and remote configuration
• Optional AquaXact aluminum oxide (Al₂O₃) dew point probe integration—enabling simultaneous O₂ and moisture monitoring within a single instrument housing and data stream
• IP65-rated enclosure with stainless-steel gas manifold and EPDM/FFKM wetted materials compliant with ISO 8573-1 Class 1 for particle and hydrocarbon cleanliness

Sample Compatibility & Compliance

The DF-310E is validated for use with non-corrosive, dry-to-moderately humid industrial gases including nitrogen, argon, helium, hydrogen, oxygen-enriched air, and synthetic process mixtures. Sample conditioning is recommended for streams containing particulates (>0.1 µm), condensable vapors, or >10 ppm total hydrocarbons; optional inline sintered stainless-steel filters and heated sample lines are available. The analyzer meets CE marking requirements under the EU Electromagnetic Compatibility Directive 2014/30/EU and Low Voltage Directive 2014/35/EU. Its firmware architecture supports audit trail logging and user-access controls aligned with FDA 21 CFR Part 11 expectations for regulated environments. Calibration records, event logs, and configuration changes are timestamped and exportable via USB or Ethernet—supporting GLP/GMP documentation workflows in pharmaceutical, electronics, and food-grade gas production facilities.

Software & Data Management

The MonoExact platform includes embedded web server functionality accessible via standard browser over Ethernet—eliminating proprietary software dependencies. Configuration, real-time trend viewing, alarm setup (high/low, rate-of-change), and diagnostic reporting are managed through an intuitive HTML5 interface. All measurements are time-stamped with UTC synchronization (NTP-compatible) and stored internally for up to 30 days of 1-second interval data. Data export is supported in CSV and XML formats, with optional OPC UA server add-on for enterprise MES/PI System integration. Firmware updates are performed remotely via secure HTTPS, and version history—including checksum validation—is retained in device memory for regulatory review.

Applications

• On-line purity verification during nitrogen membrane or PSA plant operation
• Final quality release testing for cylinder-filling stations supplying medical, laser, or semiconductor gases
• Monitoring inert gas blanketing in chemical reactors and storage tanks
• Leak detection and purge validation in hydrogen fuel cell manufacturing lines
• Real-time O₂ control in controlled-atmosphere heat treatment furnaces
• Compliance monitoring for ISO 8573-1 Class 1–3 compressed air and process gas specifications

FAQ

What is the minimum detectable oxygen concentration in high-resolution mode?
The DF-310E achieves a lower detection limit of 10 ppb (0.01 ppm) in the 0–100 ppm high-resolution range, with repeatability better than ±0.5% of reading.
Can the analyzer operate continuously in a hydrogen-rich environment?
Yes—the paramagnetic sensor is intrinsically immune to hydrogen interference and has been tested for stable performance in streams containing up to 99.999% H₂.
Is third-party calibration certification available?
Servomex provides UKAS-accredited calibration certificates (ISO/IEC 17025) upon request, including uncertainty budgets referenced to NIST SRM 1603a.
Does the AquaXact humidity probe require separate power or signal wiring?
No—it shares the same 24 VDC supply and Modbus RTU channel as the base analyzer, requiring only one conduit entry for dual-parameter deployment.
How is zero calibration performed?
Zero calibration uses certified nitrogen (<10 ppb O₂) introduced via the dedicated calibration port; automated zero sequence is triggered manually or scheduled via the web interface.