Phase-Doppler interferometry with probe-to-droplet size ratios less than unity. II. Application of the technique

Practical limitations associated with the use of small probe volumes with respect to the droplet size that is being measured by the phase-Doppler interferometry technique are discussed. An intensity-validation scheme and corresponding probe volume correction factor have been developed that reject trajectory errors and account for the rejections in calculation of the probe cross-sectional area. The intensity-validation scheme also provides a tractable method of setting the photomultiplier tube gain and laser power. Volume flux measurements in dilute sprays have shown a significant improvement over those made by standard phase-Doppler interferometry techniques at small beam waist/droplet size ratios.