testo 350 Flue Gas Analyzer

Overview

The testo 350 Flue Gas Analyzer is a modular, portable emission measurement system engineered for precision combustion analysis and regulatory-compliant flue gas monitoring in industrial, municipal, and commercial heating applications. Based on electrochemical (O₂, CO, NO, NO₂, SO₂, H₂S) and non-dispersive infrared (NDIR, CO₂) detection principles, the instrument supports simultaneous real-time quantification of up to six gas components — configurable per application requirements and regulatory mandates (e.g., EU Directive 2010/75/EU, EPA Method 3A, EN 15267-3). Its architecture integrates temperature, differential pressure, and flow velocity sensing via interchangeable probes, enabling comprehensive stack characterization including dew point calculation, excess air ratio (λ), and combustion efficiency. Designed for field deployment under variable ambient conditions, the testo 350 operates reliably between −5 °C and +45 °C, with robust thermal management and condensate-handling capabilities critical for long-duration measurements in high-moisture exhaust streams.

Key Features

• Modular sensor configuration: Minimum two gas sensors required; expandable to six independent electrochemical or NDIR channels.
• H₂-compensated CO and CO_low sensors ensure accurate carbon monoxide measurement in hydrogen-rich combustion environments (e.g., biomass, syngas, fuel cells).
• NDIR-based CO₂ measurement with built-in absolute pressure compensation and integrated CO₂ absorption filter for stable baseline performance over extended operation.
• Peltier-cooled gas conditioning module (optional) enables automated condensate separation and sample drying — essential for >2-hour continuous monitoring per EN 14181 QA/QC requirements.
• Fresh air valve option provides 5× dynamic range extension for low-concentration gas measurement without manual dilution or recalibration.
• Single-channel range extender supports programmable amplification factors (0×, 2×, 5×, 10×, 20×, 40×) for optimized signal-to-noise ratio across diverse concentration regimes.
• Integrated data logging (2 MB memory, 250,000 values) with timestamp, GPS tagging (via Bluetooth), and automatic metadata capture (probe ID, calibration status, ambient conditions).
• IP40-rated housing with ergonomic hand-held design (440 g) and hot-swap battery support for uninterrupted field operation.

Sample Compatibility & Compliance

The testo 350 is validated for use with flue gases from fossil-fueled boilers, waste incinerators, gas turbines, and biomass combustion systems. Its sensor configuration meets technical specifications outlined in EN 15267-3 (type approval for automated measuring systems), ISO 12039 (CO, CO₂, NOₓ, SO₂ determination), and VDI 3862 (emission monitoring in small-scale combustion plants). Electrochemical sensors conform to IEC 62941 for stability and cross-sensitivity control; NDIR CO₂ measurement complies with ISO 4037-2 traceability requirements. The instrument supports GLP-compliant workflows through audit-trail-enabled calibration logging, user-access-level controls, and firmware-locked calibration parameters. Optional Peltier conditioning ensures compliance with EN 14181 QAL2 (quality assurance level 2) for continuous emission monitoring systems (CEMS) verification.

Software & Data Management

Data acquisition and reporting are managed via testo’s proprietary testo EasyEmission software (Windows/macOS), which supports automated report generation per DIN EN 14181 Annex A and EPA 40 CFR Part 60. The software imports raw measurement files (.tdf), applies correction algorithms (e.g., dry/wet basis conversion, stoichiometric λ calculation), and exports PDF/CSV outputs compliant with environmental agency submission formats. Wireless connectivity (Bluetooth 4.2) enables live telemetry to tablets or laptops during sampling. All calibration events — including zero/span checks, sensor replacement logs, and drift verification — are digitally signed and time-stamped, satisfying FDA 21 CFR Part 11 electronic record requirements when used in regulated facilities. Firmware updates preserve historical calibration coefficients and maintain metrological continuity across device lifecycles.

Applications

• Combustion optimization and boiler tuning in district heating networks and industrial steam generation.
• Emission compliance verification for medium combustion plants (MCPs) under EU 2015/2193.
• Periodic stack testing for NOₓ, SO₂, and CO per local air quality regulations (e.g., TA Luft, U.S. NSPS Subpart D).
• R&D applications in low-carbon fuel development (hydrogen blends, biogas, ammonia co-firing) requiring H₂-compensated CO and multi-gas speciation.
• Commissioning and maintenance of flue gas desulfurization (FGD) and selective catalytic reduction (SCR) systems.
• Academic and consultancy work involving flue gas composition profiling, heat loss analysis, and carbon balance calculations.

FAQ

What is the minimum sensor configuration required for operation?
The testo 350 requires at least two gas sensors installed to initialize measurement mode — typically O₂ plus one combustible or pollutant gas (e.g., CO or NO).
Is the instrument suitable for high-humidity flue gas sampling without external conditioning?
Yes, but only for short-term (<2 h) measurements. For sustained operation, the optional Peltier gas conditioning module is strongly recommended to prevent sensor saturation and condensate ingress.
How does the H₂ compensation function improve CO measurement accuracy?
It corrects for electrochemical cross-sensitivity between CO and H₂ by applying algorithmic compensation based on simultaneous H₂ partial pressure estimation — critical for syngas, landfill gas, and hydrogen-blended natural gas applications.
Can the testo 350 generate legally admissible reports for environmental authorities?
Yes, when used with validated sensors, documented calibration records, and testo EasyEmission software configured for regulatory templates (e.g., EN 15267-3 Annex B), outputs meet evidentiary standards for permitting and enforcement agencies.
What probe types are supported for temperature and flow measurement?
K-type (NiCr-Ni) and S-type thermocouples, ambient temperature probes, and pitot tube or thermal anemometer probes — all with automatic recognition and linearization in firmware.