Evaluation of a device for in-flight determination of size and distribution of hailstones

A recording instrument (distrometer) for surveying the hail environment aloft was calibrated with single simulated hailstones launched from the hailstone impact simulator. The hailstone manufacture and characteristics, impact simulator, experimental test program, and resulting data are described. Hailstones 1.3, 2.5, 3.8, and 5.1 cm in diameter were impacted on the distrometer at velocities ranging from 20 to 380 m/s. An evaluation of the distrometer based on data from these tests is presented.