Honegeagle HNAG6200-NOX-T Nitrogen Oxides (NOₓ) Online Emission Monitor

Overview

The Honegeagle HNAG6200-NOX-T is a certified continuous emission monitoring system (CEMS) designed for real-time quantification of nitrogen oxides (NO and NO₂, collectively NOₓ) in industrial flue gas and ambient air streams. Engineered for compliance-driven environmental monitoring, it employs electrochemical sensing technology—optimized for selectivity, long-term stability, and low cross-sensitivity to CO, SO₂, O₃, and hydrocarbons. The instrument operates on the principle of amperometric detection: NOₓ gases diffuse through a selective membrane into an electrolyte cell, where oxidation/reduction reactions generate a current linearly proportional to analyte concentration. This architecture ensures high reproducibility under variable temperature and humidity conditions typical of stack and fenceline applications—including boiler exhaust, desulfurization/denitrification (FGD/SCR) ducts, and unorganized emission zones in chemical, metallurgical, and coating facilities.

Key Features

• Integrated gas pre-treatment subsystem: includes thermoelectric cooling, Nafion®-based moisture removal, particulate filtration (≤0.3 µm), and pressure regulation to deliver conditioned sample gas at stable dew point (<5 °C) and flow rate (0.8–1.2 L/min)
• Electrochemical NOₓ sensor with dual-channel output: simultaneous measurement of NO and NO₂; automatic internal zero/span compensation every 24 hours
• Onboard programmable logic controller (PLC): enables configurable alarm thresholds, relay-triggered ventilation control (e.g., fan activation upon exceedance), and fail-safe shutdown protocols
• Hazardous area certification: compliant with GB3836.1–2010 (general requirements for electrical apparatus in explosive atmospheres) and GB3836.4–2010 (intrinsic safety “i” protection level)
• Modular data acquisition unit: supports RS485 (Modbus RTU), 4–20 mA analog output, and optional GPRS module for secure transmission to provincial or national environmental supervision platforms per HJ/T 212–2017
• Local data logging: internal SD card stores 12 months of 1-minute averaged concentration data with time stamping and audit trail capability

Sample Compatibility & Compliance

The HNAG6200-NOX-T is validated for use with hot, humid, and particulate-laden gas streams up to 200 °C (with external probe cooling), with inlet particulate loading ≤100 mg/m³ and condensable hydrocarbon content <50 ppmv. It meets the performance criteria specified in GB 12358–2006 for workplace gas detection instruments and aligns with emission limit enforcement frameworks including GB 16171–1996 (coke oven emissions), GB 20950–2007 (oil depot VOC/NOₓ), and GB 21902–2008 (synthetic leather industry). All firmware and data handling routines support GLP-aligned record integrity—full traceability of calibration events, operator logins, and configuration changes is retained for regulatory audits.

Software & Data Management

The system interfaces with Honegeagle’s proprietary CEMS Manager v3.2 software suite, compatible with Windows 10/11 and supporting OPC UA connectivity for integration into SCADA or DCS environments. Data export formats include CSV, XML, and PDF reports compliant with HJ/T 212–2017 transmission protocol. Audit logs record all user actions with timestamps and IP addresses; electronic signatures are supported for calibration verification. Optional FDA 21 CFR Part 11-compliant modules provide role-based access control, electronic signature workflows, and immutable archive storage—suitable for facilities operating under ISO 14001 or IEC 61511 functional safety requirements.

Applications

• Continuous monitoring of NOₓ emissions from coal-fired and biomass boilers in thermal power plants
• Fenceline monitoring at petrochemical refineries and catalytic cracking units per DB44/1837 (container manufacturing) and DB44/816 (automotive coating)
• Compliance verification for SCR/SNCR denitrification systems in cement kilns and waste incinerators
• Real-time reporting to provincial Environmental Monitoring Centers via GPRS or fiber-optic telemetry
• Stack testing and QA/QC validation during periodic inspection cycles mandated by local ecological bureaus

FAQ

What NOₓ species does the HNAG6200-NOX-T measure?
It measures both nitric oxide (NO) and nitrogen dioxide (NO₂) independently using dual electrochemical cells calibrated against NIST-traceable standard gases.
Is the system certified for use in Zone 1 hazardous areas?
Yes—certified to GB3836.4–2010 intrinsic safety “ia” rating for Group II C (hydrogen/acetylene) atmospheres.
Can the device store historical data without external PC connection?
Yes—internal microSD card retains ≥1 million data points with configurable sampling intervals (1 sec to 60 min) and automatic rollover.
Does the pre-treatment system require consumables?
The Nafion dryer membrane and particulate filter cartridges require replacement every 6–12 months depending on dust load; no chemical reagents or electrolyte refills are needed.
How is remote calibration performed?
Via Modbus command or web interface: users initiate zero calibration with synthetic air or span calibration with certified NO/NO₂ gas mixtures; all events are logged with digital signatures.