Abstract: The invention relates to a ball launcher constituted by a body having an opening for receiving the ball and an opening for introducing the ball at the inlet of the loop, and comprising a valve cooperating with a seat, wherein said valve is fast in rotation with a pin located at a distance from this valve and parallel to its plane, and it may thus move inside the launcher between two end positions, said valve being hermetically applied against the seat in its first end position, and allowing the ball to abut on said seat in a second end position, the return of the valve to its first end position ensuring forced passage of the ball through the seat. The invention is more particularly applicable to the calibration of volume meters.