TY - JOUR
TI - A REVIEW ON THE ACCURATE MEASUREMENT OF PARTICLE SIZE AND REFRACTIVE INDEX WITH INNOVATIVE PHASE-DOPPLER ANEMOMETERS
AU - Brenn Günter
AU - Xu Tian-Hua
JN - Thermal Science
PY - 2001
VL - 5
IS - 1
SP - 101
EP - 113
PT - Article
AB - Considerable research work published in the first half of the 1990s on the Gaussian beam defect and its influence on results of phase-Doppler measurements provided deep understanding of its influence on phase-Doppler anemometry that time [1, 2]. 
This research has even led to the development of new kinds of PDA systems that are able to eliminate the influence of the defect on the measurement results. The resultant so-called Dual Mode PDA enables such error-free measurements, and, further to that achievement, the feasibility of refractive-index measurements with this system has been taken into consideration.  The present paper summarizes the basics of the Gaussian beam defect in  phase-Doppler anemometry and achievements in measuring the particle refractive index using phase-Doppler techniques. 
The role of making the Gaussian beam defect a usable effect is particularly accounted for.