摘要 |
Disclosed is a seismic source device, known in the industry as an air gun, having shuttle control for allowing a predetermined discharge of compressed air into water for purposes of seismic exploration. The shuttle is indirectly controlled by a moveable plate for closing the exhaust ports before all of the compressed air in the firing chamber of the air gun is exhausted. In one embodiment, the plate is freely moveable; in a second embodiment, the plate is attached to the shuttle. By preventing further discharge of air, with little or no loss in acoustic output, secondary pulses are greatly reduced, thereby enhancing the operation of the entire system. Further by preventing all the air in the firing chamber from being discharged, the system becomes more efficient and more cost effective.
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