CUBIC Gasboard-3500 TDLAS-Based Multi-Gas Emission Analyzer for Landfill and Industrial Process Monitoring
| Brand | CUBIC INSTRUMENTS |
|---|---|
| Model | Gasboard-3500 |
| Measurement Principle | Tunable Diode Laser Absorption Spectroscopy (TDLAS) |
| Measured Gases | O₂, CO, CO₂, H₂S, CH₄ |
| Detection Ranges | O₂ (0–100% vol, down to 1 ppm), CO (0–100% vol, down to 0.1 ppm), CO₂ (0–100% vol, down to 0.1 ppm), H₂S (0–1% vol, down to 0.1 ppm), CH₄ (0–100% vol, down to 0.1 ppm) |
| Accuracy | ±0.5–2% F.S. depending on gas and range |
| Response Time | <40 s (at 2 L/min) |
| Sample Flow Rate | 0.7–1.2 L/min (optimal), up to 2 L/min |
| Explosion Protection | Ex db IIC T6 Gb / Ex tb IIIC T80°C Db |
| Output Interfaces | RS-485, RS-232, 4–20 mA analog |
| Power Supply | AC 220 V, 50 Hz |
| Display | Integrated LCD |
Overview
The CUBIC Gasboard-3500 is a certified intrinsically safe, multi-component gas emission analyzer engineered for continuous, real-time monitoring of landfill biogas and industrial process streams. It employs Tunable Diode Laser Absorption Spectroscopy (TDLAS)—a physics-based, line-of-sight optical technique that quantifies trace and major gas species via high-resolution absorption spectroscopy at near-infrared wavelengths. Unlike electrochemical or catalytic bead sensors, TDLAS provides inherent selectivity, eliminating cross-sensitivity from humidity, particulates, or background gases. The instrument is specifically designed for deployment in harsh, unconditioned sample environments: its integrated front-end pretreatment module removes moisture and particulate load prior to optical measurement, enabling stable operation in raw landfill gas, flare stack effluents, biogas upgrading units, and refinery off-gas lines. Its dual-certified explosion protection (Ex db IIC T6 Gb for gas atmospheres and Ex tb IIIC T80°C Db for combustible dust environments) ensures compliance with IEC 60079-0, -1, and -31 standards—making it suitable for Zone 1/21 hazardous locations across waste management, petrochemical, and LNG infrastructure.
Key Features
- TDLAS-based optical detection with zero moving parts in the measurement path—ensuring long-term stability and minimal drift over extended calibration intervals
- Simultaneous, independent quantification of five critical gases: O₂, CO, CO₂, H₂S, and CH₄—each with configurable range selection to match application-specific concentration profiles
- On-board zero calibration using integrated air pump and reference path—enabling automatic daily or event-triggered baseline correction without external gas cylinders
- Embedded self-diagnostic engine continuously monitors laser intensity, photodetector signal-to-noise ratio, optical alignment status, and flow integrity—reporting fault codes via Modbus or local display
- Ruggedized housing with IP65-rated enclosure and stainless-steel wetted materials compatible with corrosive biogas constituents (e.g., H₂S ≤ 1000 ppm)
- Low-maintenance architecture: no consumables, no filters requiring routine replacement, and no optical windows exposed to raw sample stream
Sample Compatibility & Compliance
The Gasboard-3500 accepts raw, humid, and particulate-laden sample gas streams up to 95% RH and 5 mg/m³ dust loading—conditions typical of untreated landfill gas extraction wells or anaerobic digester headspace. Its integrated heated sampling line (optional) and cyclonic pre-filter mitigate condensation and entrained solids upstream of the optical cell. All measurement data comply with ISO 14064-1 requirements for GHG inventory reporting and support verification under EPA Method 2C and EN 15267-3 for continuous emission monitoring systems (CEMS). The analyzer meets electromagnetic compatibility (EMC) per IEC 61326-1 and carries CE marking for industrial use within the European Economic Area. For regulated pharmaceutical or food-grade biogas applications, optional audit-trail-enabled firmware supports FDA 21 CFR Part 11 compliance when paired with validated data acquisition software.
Software & Data Management
The device supports native Modbus RTU/ASCII over RS-485 and ASCII protocol over RS-232 for integration into SCADA, DCS, or PLC-based control networks. Analog 4–20 mA outputs are individually assignable per gas channel with HART-compatible configuration. Local data logging stores up to 30 days of 1-minute averaged readings (O₂, CO, CO₂, H₂S, CH₄, temperature, pressure, flow) on internal flash memory. Remote access is enabled via optional Ethernet gateway with secure HTTPS/TLS interface. Firmware updates and configuration changes are performed through CUBIC’s PC-based GasConfig v4.2 utility—validated for Windows 10/11 and compliant with GLP documentation standards, including electronic signature capture and change history retention.
Applications
- Landfill gas collection and flaring efficiency monitoring—tracking CH₄ oxidation completeness and detecting fugitive emissions
- Biogas upgrading plants—controlling amine scrubber or membrane separation performance via real-time H₂S and CO₂ slip detection
- Refinery fuel gas header analysis—ensuring combustion safety by verifying O₂ dilution and detecting CO breakthrough during thermal oxidizer operation
- LNG terminal BOG (boil-off gas) composition verification prior to reinjection or flare diversion
- Wastewater treatment plant anaerobic digester off-gas monitoring for process optimization and corrosion risk assessment
- Coal mine ventilation air methane (VAM) abatement system feedback control
FAQ
What gas standards are required for calibration verification?
Certified reference gases traceable to NIST or national metrology institutes (e.g., China NIM) are required. Mixtures must be prepared in ultra-high-purity nitrogen (≥99.999%) and certified for each target analyte at the selected measurement range.
Can the Gasboard-3500 operate without external zero gas supply?
Yes—the built-in air pump draws ambient air through a particulate filter and delivers it to the optical cell for automated zero calibration, eliminating dependency on bottled zero gas.
Is the instrument suitable for outdoor installation in freezing conditions?
With optional heated sample line and cabinet heating kit (operating range: −20°C to +50°C), the analyzer maintains specified accuracy and mechanical integrity in sub-zero ambient environments.
How is measurement traceability maintained for regulatory reporting?
Each unit ships with a factory calibration certificate referencing ISO/IEC 17025-accredited calibration data. Optional on-site validation services include third-party witnessed span checks and drift verification per EN 14181 QAL1/QAL2 protocols.
Does the system support remote firmware updates and diagnostics?
Yes—via secure TLS-encrypted connection through the optional Ethernet communication module; all update logs, diagnostic events, and configuration changes are timestamped and stored with user attribution for audit readiness.
