Development of an open-path incoherent broadband cavity-enhanced spectroscopy based instrument for simultaneous measurement of HONO and NO2 in ambient air

Simultaneous monitoring of temporal profiles of NO3, NO2 and O3 by incoherent broadband cavity enhanced absorption spectroscopy for atmospheric applications

“…For weak absorbers in a Rayleigh environment (no aerosols), the effective path length depends on the mirrors reflectivity, the Rayleigh extinction coefficient and the distance between the two cavity mirrors; it can be expressed as follows [25,28].…”

“…Precise knowledge of the mirror reflectivity over the whole investigated wavelength range is indispensable for determination of absolute extinction coefficients. The cavity mirror reflectivity can be determined by means of an absorber with known concentration, such as NO 2 or O 3 [21,24,25] or using Rayleigh spectra of two different absorbers, such as CO 2 , N 2 or He [23,29].…”

“…Brown et al developed a CRDS based analytical instrument for field observation of NO 3 and N 2 O 5 with a detection sensitivity of 0.5 pptv (in 5 s integration time) for both species [10][11][12]. The IBBCEAS technique was first introduced in 2003 by Fiedler et al [13] and has since been adopted by different groups [14][15][16][17][18][19][20][21][22][23][24][25]. The lowest detection limit reported for NO 3 is 0.25 pptv measured around 662 nm for 10 s acquisition time [16].…”

Environmental Application of High Sensitive Gas Sensors with Tunable Diode Laser Absorption Spectroscopy

“…Good understanding of HONO sources and sinks requires instruments capable of performing high sensitivity, high precision, high specificity, high spatial resolution, and fast in situ measurements. Among various analytical instruments developed for field HONO monitoring [76][77][78], spectroscopic detection techniques capable of performing in situ measurements without any sample preparation have been increasingly developed since last decade as an attractive alternative for quantitative assessments of HONO in the atmosphere. Methods such as DOAS, incoherent broadband cavity-enhanced absorption spectroscopy (IBBCEAS), and the long-path absorption photometer (LOPAP) used in the ultraviolet region usually can get several hundred ppt-level detection limits, but the integration time of several minutes is long and cannot satisfy the requirement of fast measurements [6,79].…”

Development of an incoherent broadband cavity enhanced absorption spectrometer for in situ measurements of HONO and NO<sub>2</sub> in China

“…IBBCEAS has gradually been applied to the study of HONO Wu et al, 2011;Wu et al, 2014;Reeser et al, 2013;Scharko et al, 2014;Min et al, 10 2016),with continued improvements in sensitivity.…”