The LEVIFLOW® LFS-SU inline sensor is designed for non-invasive, high precision flow measurements in bioprocessing. Two piezoelectric transducers generate and receive ultrasonic waves. When flow is present, the with-stream wave is accelerated, and the against-stream wave is slowed down. The difference in transit time is proportional to the velocity of the fluid. All wet materials are fabricated from biocompatible (FDA, USP-VI, and BSE/TSE free) gamma robust polypropylene (PP). For accurate measurement down to the lowest flows, special calibrated versions are available.