Abstract
A quantitative measurement of laser light extinction during particle growth in an expansion chamber of a condensation nuclei counter was performed. The attenuated light flux and the light flux scattered at a selectable scattering angle are monitored simultaneously during the particle growth process. From the transmitted light flux vs time the light extinction during particle growth can be determined quantitatively. The experimental scattered light flux vs time allows a precise determination of particle sizes at various times during particle growth. Knowing the actual particle size, the light attenuation obtained from the transmitted light flux allows a direct, quantitative determination of particle number concentration without referring to any calibration of the apparatus.Measurements have been performed over a range of aerosol number concentrations and compared with two different techniques. The results obtained show that the simultaneous observation of transmitted and scattered light permits an absolute aerosol number concentration measurement.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
