摘要 |
The invention relates to an ultrasonic flow sensor, particularly for measuring the volume flow rate or mass flow rate of a fluid (1). The sensor comprises two ultrasonic transducers (A, B), which are arranged in an offset manner in the direction of flow (2) and which each transmit an ultrasonic signal (An, Bn) to the other ultrasonic transducer (A, B). A measured quantity (S) is determined from the transit times (t<SUB>12</SUB>, t<SUB>21</SUB>) of the ultrasonic signals (An, Bn). The accuracy of the flow sensor can be significantly improved by the provision of a controlling and evaluating unit (4) that, when an ultrasonic signal (A1, B1) is received by one of the ultrasonic transducers (A, B), detects a number of receiving times (t<SUB>i</SUB>', t<SUB>i</SUB>') per signal (A1, B1) each time from which the measured quantity (S) is obtained. |