Highly range-resolved ammonia detection using near-field picosecond differential absorption lidar

Ammonia detection is highly relevant for combustion in boilers and furnaces since NH3 is able to suppress nitric oxide levels by catalytic as well as non-catalytic reduction. The mixing of ammonia with flue gases is an important parameter to obtain efficient non-catalytic reduction. In this paper picosecond DIAL was used for range-resolved, single ended, NH3 detection, utilizing a tunable picosecond laser source. The absorption spectrum of the A(ν2 = 1)←X(ν2 = 0) band was recorded and 212.2 and 214.5 nm was selected as the on- and off-resonance wavelength, respectively. One-dimensional concentration profiles with various NH3 concentration distributions are presented. The detection limit was found to be 40 ppm with a spatial resolution of 16 cm.