Eranntex MS500-SO2 Handheld Sulfur Dioxide (SO₂) Gas Detector

Overview

The Eranntex MS500-SO2 is a professional-grade handheld sulfur dioxide (SO₂) gas detector engineered for field-deployable, real-time environmental and industrial hygiene monitoring. It employs a high-selectivity electrochemical sensing principle—optimized for SO₂ detection in ambient air, flue gas ducts, confined spaces, and emission control points—where rapid response, measurement stability, and trace-level resolution are critical. The instrument conforms to fundamental metrological requirements defined in GB 15322.3–2019 for portable toxic gas detectors and integrates intrinsic safety design per GB 3836.1–2010 and GB 3836.4–2010, certified as Ex ia IIC T4 Ga for use in Zone 0/1 hazardous areas. Its dual-range capability (0–10 ppm and 0–100 ppm) supports both occupational exposure limit (OEL) verification (e.g., OSHA PEL = 5 ppm, ACGIH TLV = 2 ppm) and higher-concentration process leak detection. The built-in micro-pump enables active sampling up to 10 meters from the instrument, with pressure-compensated flow control suitable for negative or positive pressure environments (−0.5 to +2 bar), ensuring representative sample acquisition without dilution or bias.

Key Features

• High-fidelity electrochemical SO₂ sensor from globally recognized suppliers (Honeywell, Figaro, City Technology, Alphasense, Dynament, Membrapor)
• 2.5-inch high-resolution color TFT display with multi-mode visualization: simultaneous 4-gas view, large-font single-channel mode, and real-time concentration curve plotting
• IP66-rated enclosure with integrated hydrophobic dust/water filter—validated for continuous operation in high-humidity (up to 100% RH) and high-particulate environments
• Intelligent auto-zero tracking and multi-point calibration support—enabling long-term baseline stability and traceable linearity across full scale
• Configurable alarm logic: low/high, TWA/STEL-weighted, interval, and dual-threshold modes—with visual (LED flash), audible (90–120 dB), vibratory, and backlit screen alerts
• Robust power architecture: 6000 mAh rechargeable Li-polymer battery with 5-level SOC indicator, overcharge/overdischarge/short-circuit/thermal protection, and hot-swap USB charging (compatible with standard 5 V USB power sources)
• Expandable data logging: internal storage for ≥100,000 timestamped records; supports real-time, timed, or event-triggered (alarm-only) capture
• Multi-interface connectivity: USB-C (data transfer + charging), RS232 (optional), and infrared (IRDA, optional)—compatible with PC-based analysis software for compliance reporting and trend evaluation

Sample Compatibility & Compliance

The MS500-SO2 is validated for direct sampling of ambient air, stack effluents, and process streams where SO₂ concentrations fall within its configured range. It accommodates variable matrix conditions—including nitrogen- or oxygen-dominant backgrounds—and tolerates transient exposure to condensable vapors when equipped with the standard hydrophobic particulate filter. For elevated-temperature applications (e.g., boiler flue gas), optional high-temperature sampling accessories—such as the cooled probe with integrated thermal quenching and particulate filtration—are available to extend operational limits up to 800 °C. All configurations meet Chinese national standards for portable gas detection instrumentation (GB 15322.3–2019) and intrinsic safety (GB 3836 series). While not CE-marked or FDA 21 CFR Part 11-compliant out-of-the-box, the device’s audit-ready data log structure, time-stamped calibration history, and firmware-traceable configuration changes support integration into GLP/GMP-aligned workflows when deployed with validated procedures.

Software & Data Management

Data export and post-processing are supported via proprietary Windows-compatible desktop software delivered on included USB drive. The application enables full retrieval of stored measurements—including date/time stamps, temperature/humidity readings (if enabled), alarm status flags, and battery voltage logs. Users may generate PDF reports with customizable headers (company name, site ID, operator ID), annotate test conditions, and apply statistical filters (e.g., min/max/avg per hour). Raw CSV exports facilitate third-party integration with LIMS or enterprise environmental management systems (EMS). Firmware updates are performed via USB, with version rollback capability and SHA-256 checksum validation to ensure integrity. Calibration and maintenance events—including sensor replacement, span adjustment, and zero verification—are automatically logged with operator ID (if entered), timestamp, and pass/fail outcome—supporting ISO 17025 traceability requirements.

Applications

• Ambient air quality monitoring near coal-fired power plants, smelters, and sulfuric acid production facilities
• Occupational health surveillance in pulp & paper mills, wastewater treatment plants, and wineries where SO₂ is used as a preservative
• Leak detection during SO₂ transport, storage, and cylinder handling in chemical distribution centers
• Stack emission auditing and CEMS verification in compliance with local environmental regulations
• Confined space entry pre-screening in industrial maintenance scenarios (e.g., scrubber vessels, desulfurization units)
• Field validation of fixed-site SO₂ analyzers during commissioning or periodic performance checks

FAQ

What is the typical service life of the electrochemical SO₂ sensor?
Standard sensors exhibit a functional lifespan of 24–36 months under normal operating conditions (25 °C, 50% RH, <1 ppm average exposure). Lifespan decreases with sustained exposure to high concentrations (>50% of full scale), extreme temperatures, or corrosive co-contaminants (e.g., Cl₂, NO₂, H₂S).
Can the instrument measure SO₂ in high-humidity flue gas without condensation damage?
Yes—the integrated hydrophobic membrane filter prevents liquid ingress, and the sealed sensor chamber maintains operational integrity at 0–100% RH. For saturated steam environments, pairing with the optional high-temperature cooled probe is recommended.
Is multi-gas configuration supported out of the box?
The MS500 platform supports up to five simultaneous gases; however, the MS500-SO2 variant ships calibrated and optimized for SO₂ only. Additional gas channels require factory configuration and sensor installation—contact Eranntex technical support for cross-sensitivity assessment and multi-gas calibration protocols.
Does the device support regulatory audit trails for calibration and maintenance?
Yes—each calibration event (zero/span), sensor replacement, and firmware update is permanently recorded with UTC timestamp, operator input (optional), and result status. These logs are non-erasable and exportable for regulatory review.
How is temperature compensation implemented for SO₂ measurement accuracy?
An NTC thermistor measures sample gas temperature in real time; the embedded algorithm applies a polynomial correction factor derived from sensor-specific characterization data—ensuring ≤±2% FS accuracy across the full −40 °C to +70 °C operating range.