Standard source of atmospheric black carbon aerosol generated from ultrasonic spray of BC suspension

Abstract

Black carbon (BC) aerosol has strong radiative forcing and plays an important role in global climate change and human health. A generator with low levels of BC-air is developed in this study for researchers to calibrate BC monitors. Ultrasonic nozzle is applied to atomize BC suspension to produce quantificational BC-air samples which can be 10 used directly as a standard source of BC. Membrane test conducted by balance is used to check up its feasibility. Results show that the relationship of weight increment of membrane and target concentration of BC -air have very good linearity. This confirms that the ultrasonic spray system is a good source to generate standard concentration of BC-air. The device has good feasibility in the BC concentrations range of 0-200 μgm -3 . Multi Angle Absorption Photometer (MAAP) is used to detect the concentration of BC-air generated by the ultrasonic spray of suspension. Target concentrations generated 15 by the device accord with the measured data of MAAP.