Improving phase Doppler volume flux measurements in low data rate applications

Phase Doppler interferometry (PDI) measurements in low number density spray s necessitate a compromise between collecting a large number of samples for adequate statistics and practical data acquisition times. This paper inves tigates the effect of insufficient sample statistics on the calculated prob e area, and the resultant uncertainty in the volume flux measurement. Sever al methods of improving the probe area calculation and volume flux measurem ent are investigated using experimental data obtained from water sprays pro duced by residential fire sprinklers. It is shown that the corrections resu lt in statistically significant improvements in the volume flux measurement s.