| 摘要 |
<p>A fluid-filled network of connected conduits and valves receives an acoustic signal in the form of waves of predetermined frequency, amplitude, and time sequence. At a second location, an acoustic receiver senses the form of the waves in frequency, amplitude, and time sequence arriving from the transmitter. The comparison between the acoustic signal introduced into the network and the signal received from the network represents whether the valve settings are satisfactory for using the network as a unit.</p> |
