Direct Detection of NO₂: Applications and Performance of a Dual-Channel NO₂/NOx Analyzer in Emissions and Field Monitoring

Abstract Description: Nitrogen dioxide (NO₂) is a known toxic gas and it emitted from combustion sources alongside nitric oxide (NO) into the atmosphere which affects human health and the ecosystem. As climate change becomes has become more center stage in our lives, accurate monitoring of nitrogen dioxide (NO₂) is more critical than ever in our quest to create cleaner air for future generations and mitigate the associated health impacts of air pollution. In this work, a new instrument, Direct Optics G60 Dual Channel NO₂ and NOx analyzer has been designed to meet the rigorous demands of continuous emissions monitoring systems (CEMS) and ambient air quality assessments. This study highlights its deployment and performance across diverse application scenarios.

In a CEMS environment, the instrument was integrated with a dilution sampling system, enabling the measurement of diluted gas concentrations extracted from industrial stacks. Technical audits, including Cylinder Gas Audits (CGA) and Relative Accuracy Test Audits (RATA), were conducted to validate its performance under high-precision conditions. Additionally, the instrument underwent extensive field trials in Vernal, USA, where it operated continuously for over 11 months. The analyzer demonstrated robust performance, adhering to all planned calibration and maintenance schedules.
Comparative results from these deployments will be presented, showcasing the instrument’s accuracy, reliability, and maintenance efficiency. The study also explores the challenges and opportunities identified during co-located studies, particularly regarding calibration protocols and environmental influences. These findings underline the critical role of advanced monitoring technologies in addressing global air quality challenges.