25th European Conference on Liquid Atomization and Spray Systems, Chania, Greece, 1-4 September 2013
The Time-shift technique for characterization of non-transparent, spherical particles
Abstract
The time-shift technique, also known as the pulsed-displacement technique, is re-visited as a means of
measuring size, velocity and relative refractive index of spherical, non-transparent particles. Building on the basic measurement principle, several new innovations are introduced, making the technique significantly more attractive for use outside of the laboratory. These include validation criteria for two-detector arrangements, and approaches for achieving higher size bandwidths, in particular lower measurable sizes. However, the main novelty introduced in this contribution is the ability to measure non-transparent droplets. Such droplets are quite common, for example in spray drying processing or in paint sprays. In this contribution the basic working principle of the time-shift techniques will be reviewed, followed by guidelines for the optical layout. Example measurements are presented.