A method is employed to couple non-invasive transducers to pipes and tubes so that flow in the conduits can be measured using the ultrasonic transit time technique. The transducers can be configured as a slot or as a clamp on device that can be designed to conform to the shape of the conduit. The transducers can send and receive ultrasonic waves in the conduits non-invasively and measure the flowrate etc. Lingli Liu, Strain Measurement Devices Innovation Video Briefs