| 摘要 |
<p>A means for detecting the presence of particulate material, e.g., sand, in a fluid stream flowing through a conduit, said means comprising an acoustical probe which is positioned directly into the flow stream. The probe has a housing in which a transducer, e.g., piezoelectric crystal, is suspended. The housing is filled with oil to acoustically couple the transducer to the housing. Particulate material in the flow stream gives up kinetic energy upon striking the housing of the probe which in turn excites the transducer to generate an output signal having a frequency component which is representative of the particulate material.</p> |
