Abstract: An ultrasonic flow meter for determining the flow rate of fluid flowing through tubings. The ultrasonic flow meter comprises a measuring tube having a diameter constant in its entire length, and two ring shaped oscillators disposed longitudinally along the tube so as to substantially intimately contact the inner peripheral surface thereof with the outer peripheral surface of the tube. The one of said two oscillators is energized by electric AC energy to generate an ultrasonic wave, and the thus generated ultrasonic wave is detected by means of the other oscillator, and vice versa. Then the time required for propagating the ultrasonic wave from the upstream oscillator to the downstream oscillator, and that from the downstream oscillator to the upstream oscillator is measured, and the difference between the measured times is calculated by means of an arithmetric circuit to determine the velocity of the fluid flowing through the measuring tube.

Abstract: An ultrasonic flow meter for determining the flow rate of fluid flowing through tubings. The ultrasonic flow meter comprises a measuring tube having a diameter constant in its entire length, and three ring shaped oscillators disposed longitudinally along the tube so as to intimately contact the inner peripheral surface thereof with the outer peripheral surface of the tube. The central oscillator of said three oscillators is energized by electric AC energy to generate an ultrasonic wave. The thus generated ultrasonic wave is detected by means of forward and rearward oscillators. The ultrasonic wave detected by the forward oscillator and that detected by the rearward oscillator are processed by means of a comparator to obtain the flow rate of the fluid flowing through the measuring tube.