Overview
The trace (ppm-level) NO2 gas analyzer is designed for continuous, quantitative monitoring of trace nitrogen dioxide. It is widely used in municipal solid waste incineration, hazardous waste disposal, diesel engine exhaust testing (post-SCR), nitric acid manufacturing, and continuous emission monitoring systems (CEMS). Delivering precise measurements of NO2 in flue gas and process streams, it enables the accurate assessment of total NOx without converter errors, tracks NO-to-NO2 oxidation efficiency, and optimizes advanced multi-pollutant scrubbing processes.
Principle
UV-LED radiation is divided into measurement and reference paths by a beam splitter. The reference beam directly reaches the detector, which converts it into a reference voltage value. Using this reference signal, the aging effect of UV-LED can be almost completely compensated. The measuring beam enters the sample cell, and the gas in the sample cell is absorbed by the radiation in it. The absorption behavior is recorded by the measuring detector and used to calculate the gas concentration in the measuring cuvette.
Application
• True NOx Continuous Emission Monitoring (CEMS)
Direct NO2 Compliance Monitoring: Measuring low-concentration NO2 directly in exhaust stacks (especially in waste-to-energy and hazardous waste incinerators) to ensure strict compliance with direct NO2 and total NOx emission limits.
Eliminating Converter Bias: Providing direct NO2 measurements to replace traditional NOx converters, eliminating measurement errors caused by incomplete conversion or converter degradation.
• Engine Testing & Mobile Source Emissions
Diesel Engine & Vehicles Exhaust: Analyzing NO2 levels in diesel engine test benches, as diesel oxidation catalysts (DOC) intentionally convert NO to NO2 to promote passive soot regeneration in diesel particulate filters (DPF).
Post-SCR Cleanliness Verification: Monitoring NO2 slip after Selective Catalytic Reduction (SCR) systems in automotive and marine applications.
• Advanced & Oxidative DeNOx Process Control
Ozone/Peroxide Injection Systems: Monitoring NO2 concentration in advanced flue gas treatment processes where ozone (O3) or hydrogen peroxide (H2O2) is injected to oxidize insoluble NO into highly soluble NO2 for wet scrubbing.
Optimal NO/NO2 Ratio Tuning: Assisting in maintaining the ideal 1:1 ratio of NO to NO2 required for the "Fast SCR" reaction, significantly increasing low-temperature denitrification efficiency.
• Chemical & Nitric Acid Production
Nitric Acid Tail Gas Control: Continuous measurement of OH/NO2 balance and trace NO2 leakage in absorption towers during nitric acid and ammonium nitrate fertilizer manufacturing.
Chemical Synthesis Process Monitoring: Tracking NO2 as a reactant or byproduct in organic nitration reactions and rocket propellant handling facilities.
Measurement components and ranges
• NO2: 0 ~ 10ppm up to 5,000ppm
For detailed introduction, please refer to Ultraviolet photometry analyzer.