CUBIC INSTRUMENTS Gasboard-3500 Ex-rated Infrared & Electrochemical Multi-gas Analyzer

Overview

The CUBIC INSTRUMENTS Gasboard-3500 is an intrinsically robust, Ex-rated online multi-gas analyzer engineered for continuous, real-time measurement of combustible and toxic gas concentrations in demanding industrial environments. It integrates dual-sensing modalities: non-dispersive infrared (NDIR) spectroscopy for quantitative analysis of CO, CO₂, CH₄, and C₃H₈; and high-stability electrochemical detection for O₂ and H₂S. This hybrid architecture eliminates cross-sensitivity between co-measured species—particularly critical when monitoring methane (CH₄) alongside carbon monoxide or hydrogen sulfide in biogas streams or landfill off-gas. The instrument incorporates an integrated sample conditioning system with particulate filtration, moisture removal, and pressure regulation—enabling reliable operation under high-humidity, dusty, or variable-pressure conditions typical of anaerobic digestion facilities, coal handling systems, and municipal waste infrastructure. Its certified flameproof enclosure (Ex d II CT6 / Ex tb IIIC T80°C Db) complies with IEC 60079-1 and IEC 60079-31 standards, permitting safe deployment in Zone 1 and Zone 21 hazardous areas without external purging or pressurization.

Key Features

• Explosion-proof design certified to Ex d II CT6 (for gas atmospheres) and Ex tb IIIC T80°C Db (for dust atmospheres), enabling direct installation in classified hazardous locations per ATEX and IECEx frameworks.
• Dual-sensor architecture: NDIR detectors with thermopile-based detection and temperature-compensated optical path ensure long-term stability and minimal drift (24 months) and built-in temperature/humidity compensation.
• Onboard zero calibration via integrated air pump and programmable auto-zero cycle—eliminating manual intervention and maintaining baseline integrity without external calibration gas cylinders.
• Full self-diagnostic capability: real-time monitoring of sensor health, optical path contamination, flow rate deviation, and power supply integrity, with event logging and configurable alarm outputs (relay, 4–20 mA, Modbus).
• Chemically inert wetted materials—including 316L stainless steel sample lines, PTFE-coated filters, and ceramic flow restrictors—ensure resistance to corrosive components (e.g., H₂S, organic acids) and particulate abrasion.
• Modular pre-processing unit with heated sample line option (up to 180°C), condensate trap, and hydrophobic membrane filter supports compliance with EPA Method 3A and ISO 12039 sampling requirements.

Sample Compatibility & Compliance

The Gasboard-3500 is validated for use with complex, unconditioned process streams containing up to 95% relative humidity, particulate loadings ≤10 mg/m³, and oil mist concentrations ≤5 mg/m³. It meets EN 50104 (O₂), EN 50105 (H₂S), and EN 61000-6-2/-6-4 electromagnetic compatibility standards. For regulatory reporting applications, its measurement traceability aligns with ISO/IEC 17025-accredited calibration practices using NIST-traceable reference gases. The device supports audit-ready data logging compliant with FDA 21 CFR Part 11 (when paired with validated SCADA software), and its firmware implements secure user authentication, electronic signature, and immutable event history—facilitating GLP/GMP-aligned operations in wastewater treatment plants and bioenergy R&D labs.

Software & Data Management

Data acquisition and remote configuration are supported via embedded Modbus RTU/TCP, ASCII serial protocol (RS-232/RS-485), and industrial Ethernet. Analog outputs (4–20 mA) are individually assignable per gas channel with scalable engineering units (e.g., % vol, ppm). Optional CUBIC Cloud Connect module enables TLS-encrypted MQTT transmission to cloud-based dashboards (e.g., ThingsBoard, Ignition) with configurable alerting, trend visualization, and automated report generation (PDF/CSV). Local storage retains ≥30 days of 1-minute averaged data with timestamped metadata (flow, pressure, temperature, diagnostics)—accessible via USB export or web interface. All firmware updates are digitally signed and verified prior to installation.

Applications

• Biogas quality control: simultaneous CH₄/CO₂ ratio calculation and calorific value estimation per ISO 6976 in anaerobic digesters and landfill gas recovery systems.
• Coal mill and pulverized fuel silo safety monitoring: early detection of CO accumulation (≥10 ppm threshold) to prevent spontaneous combustion events.
• Wastewater treatment plant headspace analysis: real-time tracking of CH₄ emissions for GHG inventory reporting (IPCC Tier 2) and odorant (H₂S) compliance with local air quality ordinances.
• Thermochemical conversion research: in-situ gas composition profiling during pyrolysis, gasification, and Fischer–Tropsch synthesis experiments.
• Industrial furnace and boiler combustion optimization: O₂ trim control combined with CO/CH₄ slip monitoring to minimize excess air and reduce NOₓ formation.

FAQ

What certifications does the Gasboard-3500 hold for hazardous area installation?
It carries dual certification: Ex d II CT6 for gas environments (IEC 60079-1) and Ex tb IIIC T80°C Db for combustible dust (IEC 60079-31), valid for Zone 1 (gas) and Zone 21 (dust) per ATEX and IECEx directives.
Can the analyzer operate without external calibration gas?
Yes—it performs automatic air-based zero calibration using its internal pump and filtered ambient air intake, reducing operational dependency on certified span gases.
Is the instrument suitable for high-moisture biogas streams?
Yes—the integrated heated sample line (optional), condensate trap, and hydrophobic membrane filter maintain stable NDIR signal integrity even at saturation point, eliminating need for external chiller-dryer systems.
How is measurement traceability maintained for regulatory reporting?
Each unit ships with a factory calibration certificate referencing NIST-traceable standards; users may perform field verification using certified gas mixtures per ISO 17025 procedures, with full audit logs retained in non-volatile memory.
What maintenance intervals are recommended for routine operation?
Filter elements require replacement every 3–6 months depending on particulate load; NDIR optics should be inspected annually; electrochemical sensors are rated for ≥24 months under continuous operation at 25°C and 50% RH.