An Optical Particle-Sizing Counter for In-Situ Measurements.

A particle sizing counter is described, suitable for in-situ measurements in two phase flows of laboratory scale. It employs near-forward scatter from the focus of a He-Ne laser beam, together with pulse height-analysis of the signals from individual particles. A novel and essential feature of the technique is a numerical inversion scheme to unfold the dependence of the scattered signals on particle trajectory through the measurement volume. The inversion procedure is performed by an on-line computer, and utilizes a prior calibration with monodisperse aerosols of known size.