LESHI SE350 Portable Multi-Gas Analyzer for CO, CO₂, and O₂

Overview

The LESHI SE350 Portable Multi-Gas Analyzer is an engineered solution for on-site quantitative analysis of key combustion and process gases—including carbon monoxide (CO), carbon dioxide (CO₂), oxygen (O₂), methane (CH₄), and hydrogen (H₂)—in demanding industrial environments. Built upon a modular sensor architecture, the instrument employs non-dispersive infrared (NDIR) spectroscopy for CO, CO₂, and CH₄ detection; electrochemical sensing for O₂; and a full-compensation thermal conductivity detector (TCD) for H₂ when configured. This multi-principle approach ensures high selectivity and long-term stability across variable matrix compositions—particularly critical in syngas, blast furnace gas, coke oven gas, and converter gas streams where background interference, moisture fluctuations, and transient pressure changes are common. Unlike fixed-station analyzers, the SE350 integrates all core sampling and signal-conditioning subsystems into a single, hand-carried unit—enabling rapid deployment for commissioning verification, leak surveys, stack auditing, and periodic QA/QC checks without reliance on external infrastructure.

Key Features

• Ruggedized stainless-steel housing (ASTM A240 316L grade) with chemically resistant internal wetted parts—engineered for extended service life in corrosive, high-humidity, or particulate-laden gas streams.
• Field-cleanable three-channel NDIR optical module with temperature- and pressure-compensated signal processing—minimizing drift and maintaining ±2 % FS accuracy over 6-month calibration intervals under typical operating conditions.
• Long-life electrochemical O₂ sensor (rated >24 months in ambient air; >12 months in continuous process sampling) with built-in humidity compensation and automatic baseline correction.
• Optional full-compensation H₂ TCD—providing linear response from 0–100 % vol H₂ while rejecting cross-sensitivity to CO, CO₂, CH₄, and N₂ via dual-reference cell design.
• Integrated sampling system: self-regulating diaphragm pump (max. 1.2 L/min), calibrated rotameter, sintered stainless-steel particulate filter (5 µm), and PTFE-lined sample line (1.5 m standard).
• Onboard rechargeable lithium-ion battery (7.4 V, 4400 mAh) supporting ≥8 hours of continuous operation at 25 °C; hot-swappable battery option available for extended field missions.
• Real-time LCD display with dual-unit capability (ppm/vol%, % vol, mg/m³) and configurable alarm thresholds with visual/audible alerts per gas channel.

Sample Compatibility & Compliance

The SE350 is validated for direct analysis of raw, unconditioned process gases containing up to 90 % relative humidity and particulate loadings ≤10 mg/m³. It operates within defined safety and performance boundaries per IEC 61000-6-2 (immunity) and IEC 61000-6-4 (emissions). Optional ATEX/IECEx-certified variants (nA IIC T4 Ga) are available for use in classified hazardous areas (Zone 2/22). While not certified to USP or FDA 21 CFR Part 11, its analog and digital outputs support integration into validated environmental monitoring systems compliant with ISO 17025 and GLP/GMP audit requirements. Calibration traceability is maintained to NIST-traceable reference gas standards (certified by UKAS-accredited labs).

Software & Data Management

Data acquisition and configuration are managed via the SE350’s embedded firmware interface or optionally through LESHI’s PC-based Analyzer Control Suite (ACS v3.2). ACS enables remote setup of measurement ranges, alarm logic, zero/span schedules, and user-defined reporting templates. All measurements include timestamped metadata (date/time, battery level, pump status, sensor health flags). Raw data export supports CSV and XML formats compatible with LIMS platforms. The 4–20 mA output channels are individually scalable and isolated—facilitating connection to DCS/SCADA systems without signal degradation. Optional SD-card logging provides audit-ready records with tamper-evident file integrity checksums.

Applications

• Industrial gas quality assurance: Real-time monitoring of CO/CO₂/O₂ ratios in coke oven gas, blast furnace top gas, and basic oxygen furnace off-gas to optimize combustion efficiency and emissions control.
• Syngas composition verification during gasification startup, shutdown, and load-following operations—supporting compliance with ISO 8573-1 Class 4 particulate limits and ASTM D1945 specifications.
• Hydrogen purity assessment in refinery PSA tail gas and electrolyzer outlet streams using the integrated TCD channel with CO/CO₂ cross-interference suppression.
• Environmental compliance audits: Stack testing for O₂-corrected CO emissions per EPA Method 10 and EN 15267-3 requirements.
• Energy recovery system diagnostics: Quantifying unburnt fuel content (CO, CH₄) and excess air (O₂) in waste heat boiler inlet flue gas.
• Mobile laboratory support: Field-deployable verification of fixed CEMS installations prior to regulatory certification.

FAQ

What gas combinations can be configured on the SE350?
The base configuration supports CO, CO₂, and O₂ simultaneously. Optional modules enable addition of CH₄ or H₂—up to four gases total. Single- or dual-gas variants (e.g., CO-only or CO/O₂) are factory-configured upon order.
Is sample conditioning required before analysis?
No external conditioning is mandatory; the integrated particulate filter and corrosion-resistant flow path accommodate raw process gas. For applications with >100 ppm condensable hydrocarbons or acid gases (e.g., H₂S >5 ppm), an optional heated sample line and Nafion dryer are recommended.
How often does the instrument require calibration?
Initial calibration is performed at the factory using NIST-traceable standards. Field recalibration is recommended every 6 months—or after exposure to extreme contamination events—using certified span gases per ISO 6141.
Can the SE350 connect to a central monitoring system?
Yes. Standard 4–20 mA outputs (per gas channel) and RS232/USB interfaces allow seamless integration with PLCs, SCADA, or cloud-based IoT platforms via Modbus RTU or ASCII protocol.
What is the warranty and service coverage?
LESHI provides a 24-month limited warranty covering parts and labor for defects in materials and workmanship. Extended service plans—including annual preventive maintenance and sensor replacement programs—are available globally through authorized service centers.