Abstract: An ultrasonic detector of the type for determining the level of a liquid within a tank or the magnitude of the flow of liquid within a conduit. The detector includes a transducer that generates bursts of ultrasonic energy and receives echoes of the energy bursts. The frequency at which the transducer transmits energy bursts is automatically adjusted to substantially match the ringdown frequency of the transducer. The detector distinguishes between true echo signals and spurious echo signals by determining whether the frequency of the echo signals generated by the transducer substantially matches the frequency at which the corresponding energy bursts were transmitted.

Abstract: An ultrasonic detector of the type for determining the level of a liquid within a tank or the magnitude of the flow of liquid within a conduit. The detector includes a transducer that generates bursts of ultrasonic energy and receives echoes of the energy bursts. The frequency at which she transducer transmits energy bursts is automatically adjusted to substantially match the ringdown frequency of the transducer. The detector distinguishes between true echo signals and spurious echo signals by determining whether the frequency of the echo signals generated by the transducer substantially matches the frequency at which the corresponding energy bursts were transmitted.

Abstract: An ultrasonic detector of the type used to detect the level of a liquid or the magnitude of liquid flow within a conduit by periodically transmitting ultrasonic energy bursts and receiving echoes therefrom is controlled by a controller with a computer program having a number of routines. The routines include a range search routine that searches a defined range of the detector to locate the targets within the range. The range is searched by repeatedly transmitting energy bursts and gradually decreasing the gain of the detector after the transmission of each burst. All targets identified during the range search are then classified as being either bogus targets or the true target. This classification is made with the use of a bogus buffer in which bogus target data is stored.