By replacing the two detectors of a standard phase-Doppler anemometer (PDA)
with a charge coupled device (CCD) line scan sensor, the scattered light c
an be measured not only with high temporal but also with improved spatial r
esolution. Thereby, the quantity to be measured by PDA, the phase differenc
e Delta phi, can be determined as function of the elevation angle psi. This
allows a statistical evaluation of the received signal and permits precise
measurements of the size and velocity even of non-ideal solid particles wi
th inhomogeneous composition, aspherical shape or rough surface.
In this paper, the basis of data acquisition and evaluation is described. T
his is followed by experimental results for glass spheres with intact and d
efect surfaces and, for comparison, for water droplets. These results demon
strate the potential of this measuring device, described as a differential
phase-Doppler anemometer (DPDA).