Airborne and laboratory studies of an IAGOS instrumentation package containing a modified CAPS particle extinction monitor

Julia Perim de Faria, Ulrich Bundke, Marcel Berg, Andrew Freedman, Timothy B. Onasch, Andreas Petzold
2017 Aerosol Science and Technology  
An evaluation of the operation and performance of a Cavity Attenuated Phase-Shift Particle Extinction Monitor (CAPS PM ex ) was performed for use on board commercial aircraft as part of the research infrastructure IAGOS (In-service Aircraft for a Global Observing System, www.iagos.org). After extensive laboratory testing, a new flow system, using mass flow controllers, was installed to maintain constant purge and sample flows under low and varying pressure conditions. The instrument was then
more » ... trument was then tested for pressures as low as 200 hPa and evaluated against particle-free compressed air and CO 2 . Extinction coefficients for the studied gases were in close agreement with literature values with differences between 2.2% and 8%, proving that the CAPS technology works at low pressures. The instrument's limit of detection, with respect to 3 times the variability of the background signal for the full pressure range, was 0.2 Mm ¡1 for 60s integration time. During its first research aircraft operations, the IAGOS instrument prototype, composed of one CAPS PMex and one OPC, showed excellent results regarding the stability of the instruments and the potential for characterizing different aerosol types and for estimating the contribution of sub-and super-mm sized particles to aerosol light extinction. EDITOR Thomas Kirchstetter
doi:10.1080/02786826.2017.1355547 fatcat:few4aqr5vvbydknuloh7xrosmq