Abstract
The purpose of the present study is to enhance measurement accuracy of a Single-Tip Optical fiber Probe (S-TOP) in droplet measurement. The S-TOP only with a wedge-shaped tip enables simultaneous measurement of the diameters, velocities and number density of bubbles/droplets. To accurately measure droplets in a spray, discrimination of a touched position by the S-TOP is essential. In this study, we revealed a characteristic peak-noise (a post-signal) contained in an output signal of the S-TOP. The post-signal intensively appears when the S-TOP penetrates a droplet at its pole. We experimentally quantified the relationship between the intensity of the post-signal and the touched position. As a result, the touched positions could be easily and reasonably discriminated by the post-signal method. This new detection technique successfully improved the accuracy of the S-TOP droplet measurement; the difference in the measured results of the S-TOP and visualization becomes smaller than 5 % at most.
