Measuring Droplet Impact Energy with Piezoelectric Film


A system for measuring water droplet impact energy is described, which consists of piezoelectric film connected to a high-speed data acquisition board in a personal computer. The system converts the impact forces of individual water droplets falling onto the piezoelectric film into an output voltage, which is measured and analyzed. Eight DT3-type piezoelectric films were calibrated under laboratory conditions for kinetic energy values ranging from 0.01 × 10−3 to 1.2 × 10−3 J by releasing water droplets of various sizes from specific heights. The DT3-type piezoelectric film is effective for water droplets smaller than 4.6 mm in diameter. Results were used to produce a general model for the response of this film type. The ease of use and robustness of the system was demonstrated by measuring droplet impact forces under a lateral-move irrigation machine.