Two-Channel, Fast Time-Response CAPS NOx Monitor

We propose to build, test and deliver a two-channelnbsp;NOxnbsp;monitor (NOx= NO + NO2) suitable for deployment on on ground or aerial-based platforms. nbsp;It will provide simultaneous measurement of total NOx and NO2 concentrationsnbsp;(and thus NO by difference)nbsp;. nbsp;It will have a physical time constant of 1 second (e-1)nbsp;and provide one independent samplenbsp;per second.nbsp;nbsp;Its accuracy will be better than 5% and its precision less than 0.2 ppb in one second sampling.nbsp;nbsp;It will utilize less than 100 W power and weigh less than 25 kilograms.nbsp;nbsp;The monitor is based on Aerodyne Researchrsquo;s patented CAPS (Cavity Attenuated Phase Shift) technology which is already used to produce commercial instruments for both the research and regulatory measurement communities.nbsp;Nitrogen Dioxide is measured as a column density by NASA satellites. nbsp;Accurate and precise ground truth measurements must be made in order to provide proper interpretation of such data. nbsp;It is alsonbsp;designated as a quot;Criteria Pollutantquot; by the Clean Air Act of 1970. nbsp;The relationship between NO and NO2nbsp;is also an indicator of plumes originating from combustion systems such as aircraft and diesel engines nbsp;and nbsp;electric power generators. nbsp;The monitors currently used bynbsp;NASA deploy an outdated technology, chemiluminescence detection of NO, which is subject to numerous chemical interferences. nbsp;Furthermore, these monitors cannot provide the fast-responsenbsp;sub-ppb precision required for the measurement of fast moving plumes.