FREMGANGSMAATE TIL OG DETEKTOR FOR SEISMISK UNDERSOEKELSE

摘要

A long, flexible cable is drawn over the surface of the earth. This cable has liquid-filled detectors which are constructed as geophones (10) and are mounted on the cable at suitable spacings. The seismic cable receives the individual output signals of the geophone. Each geophone supplies an electrical output signal having a polarity which corresponds to the direction of the movement of the earth. Their output signals are transmitted to a processing device, and then it is moved into a different position and the measurement operation is repeated. The geophones have a cylindrical, hollow housing (12) with a chamber (34) in the interior. A liquid (36) of high density, e.g. mercury, mostly fills the chamber (34). The chamber has a flexible base plate (22) which forms a force-measuring or pressure-measuring transducer (27). In addition to the flexible base plate (22), the chamber (34) has a further flexible base plate (22') on the upper side, which likewise forms a measuring transducer (27'). The geophone supplies at its output terminals (56, 58) electrical signals corresponding to the seismic signals.