Work

Laser-induced fluorescence-based detection of atmospheric nitrogen dioxide and comparison of different techniques during the PARADE 2011 field campaign

Year: 2019

Type: article

Abstract: . GANDALF (Gas Analyzer for Nitrogen Dioxide Applying Laser-induced Fluorescence), a new instrument for the detection of nitrogen dioxide based on the laser-induced fluorescence (LIF) technique, is presented in this paper. GANDALF is designed for ground based and air-borne deployment with a robust calibration system. In the current setup, it uses a multi-mode diode laser (447–450 nm) and performs in situ, continuous, and autonomous measurements with a laser pulse repetition rate of 5 MHz. The performance of GANDALF was tested during the field experiment at a forested location with urban influence where NOx levels were between 0.12 and 22 parts per billion by volume (ppbv). Based on the field results, the limit of detection is estimated at 5–10 parts per trillion by volume (pptv) in 60 s at a signal to noise ratio (SNR) of 2. The overall accuracy and precision of the instrument are better than 5 % (1 σ) and 0.5 % + 3 pptv (1 σ min−1), respectively. A comparison of nitrogen dioxide measurements based on several techniques during the field campaign is presented to explore methodic differences.

Source: Atmospheric measurement techniques

DOI: 10.5194/amt-12-1461-2019