Size Calibration Corrections for the Active Scattering Aerosol Spectrometer Probe (ASASP-100X)

The response of the active scattering aerosol spectrometer probe (ASASP-100X) is affected by the optical properties of measured particles. Response functions of the ASASP-100X probe were calculated for different complex refractive indices corresponding to different types of atmospheric aerosol particles under various relative humidity conditions. Based on these response functions, corrected calibration bin diameters were determined for 15 size channels at six relative humidity values (0%, 50%, 70%, 80%, 90%, and 99%) and three typical aerosol types (rural, urban, and maritime). Sample calculations with these corrected calibration data show that a significant underestimation of the aerosol volume distribution can result if uncorrected manufacturer's size calibration data are used.