| 摘要 |
<p>Disclosed is an ultrasonic transmitter-receiver which can be made in the form of an electrically shielded cylindrical unit which can be inserted into a hole in the sidewall of an existing pipeline so as to direct ultrasonic energy across the flow therethrough. The unit can include a concave lens below the crystal which produces the ultrasonic beam for three-dimensional focusing. The unit can be connected to a pipeline without the need for replacing a portion of the pipeline to ensure proper sound impedance matching.</p> |
