Ultrasonic measurement method taking account of the quantity of gas bubbles

A measurement method for measuring the speed of a fluid, the method comprising:

• a measurement stage comprising the steps of emitting a measurement ultrasonic signal and of acquiring a main ultrasonic signal resulting from the measurement ultrasonic signal after the measurement ultrasonic signal has travelled along a path of defined length through the fluid, the main ultrasonic signal being for analyzing in order to produce a present measurement of the travel time of the measurement ultrasonic signal;
• a validation stage for validating the present measurement, the validation stage comprising the steps of acquiring a secondary ultrasonic signal also resulting from the measurement ultrasonic signal but delayed because of the presence of gas bubbles in the fluid, of evaluating one or more first parameters in the secondary ultrasonic signal that are representative of the quantity of gas bubbles in the fluid, and of validating or invalidating the present measurement as a function of the first parameter(s).