A flow meter comprising: a housing and a flow channel arranged inside the housing ; two ultrasonic transducers disposed along the flow channel and arranged at a distance from one another, wherein the first ultrasonic transducer is configured to emit an ultrasonic signal into the flow channel and the second ultrasonic transducer is configured to receive the ultrasonic signal emitted by the first ultrasonic transducer ; three reflectors arranged inside the flow channel , the three reflectors being configured to reflect the ultrasonic signal emitted by the first ultrasonic transducer multiple times on its way to the second ultrasonic transducer such that a W-shaped path of the ultrasonic signal is formed; wherein the flow channel is formed by a tubular member inside the housing ; wherein the tubular member comprises a wall having an inner surface, the reflectors being arranged on the inner surface of the wall; wherein the flow channel comprises a flow restriction member and an outlet port having a first diameter dimension , the flow restriction member being interposed between two out of the three reflectors ; wherein the flow channel has a second diameter dimension at the flow restriction member ; and characterized in that the second diameter dimension is less than sixty percent of the first diameter dimension ; and in that the W-shaped path of the ultrasonic signal defines a plane; and in that the flow restriction member has a profile in the plane defined by the W-shaped path ; and in that the profile of the flow restriction member comprises an arcuate segment ; and in that the arcuate segment has a first end and a second end, the second end being disposed opposite the first end, and an arc length dimension between the first end and the second end; and in that the arc length dimension is at least half the first diameter dimension . a housing and a flow channel arranged inside the housing ; two ultrasonic transducers disposed along the flow channel and arranged at a distance from one another, wherein the first ultrasonic transducer is configured to emit an ultrasonic signal into the flow channel and the second ultrasonic transducer is configured to receive the ultrasonic signal emitted by the first ultrasonic transducer ; three reflectors arranged inside the flow channel , the three reflectors being configured to reflect the ultrasonic signal emitted by the first ultrasonic transducer multiple times on its way to the second ultrasonic transducer such that a W-shaped path of the ultrasonic signal is formed; wherein the flow channel is formed by a tubular member inside the housing ; wherein the tubular member comprises a wall having an inner surface, the reflectors being arranged on the inner surface of the wall; wherein the flow channel comprises a flow restriction member and an outlet port having a first diameter dimension , the flow restriction member being interposed between two out of the three reflectors ; wherein the flow channel has a second diameter dimension at the flow restriction member ; and characterized in that the second diameter dimension is less than sixty percent of the first diameter dimension ; and in that the W-shaped path of the ultrasonic signal defines a plane; and in that the flow restriction member has a profile in the plane defined by the W-shaped path ; and in that the profile of the flow restriction member comprises an arcuate segment ; and in that the arcuate segment has a first end and a second end, the second end being disposed opposite the first end, and an arc length dimension between the first end and the second end; and in that the arc length dimension is at least half the first diameter dimension . <EOS>