Sonic Joker is a high resolution ultrasonic measurement device designed for the precision distance and thickness measurement in quality control. Almost any polyurethane foam can be detected with high accuracy, independent of its color and surface structure. Standard applications are thickness measurements during continuous production. The Windows based PC software SONIC TOOLS controls the measurement parameters of SONIC JOKER and has special functions for production control. Two sensor heads can be connected to one controller unit thus giving comprehensive survey and redundancy.