Abstract
A new lightweight NO2 instrument that can be flown from a tethered balloon to give vertical NO2 profiles is described. The detection principle is the chemiluminescent reaction between NO2 and a solution of luminol. The instrument is integrated with a radiosonde to also give temperature, humidity, and pressure data. Tests show the instrument is linear from 2.8 to 75 ppbv but nonlinear below 2.8 ppbv. A calibration curve is determined. The sensitivity varies directly with pressure and it has a −3.5% per degree temperature dependence. Data from trial flights as part of the PACIFIC'93 field study show NO2 data from the surface to 900 m.
