Thin liquid film thickness measurement by ultrasound

Wada, Yuki   ; Sagawa, Jun*; Hirose, Yoshiyasu*; Satou, Akira ; Shibamoto, Yasuteru ; Yonomoto, Taisuke 

In this study, ultrasound liquid film thickness measurement system is developed to measure thin liquid film thickness using a piezo element of 15 MHz and an original driving circuit by the pulse-echo method. Since our system is higher frequency than previous study, we can observe individually multi-reflected signals in the liquid film until 0.2 mm thickness and it is indicated that high accuracy liquid film thickness measurement will be possible less than 0.2 mm thickness.