of the kit for seismic research performance
High precision of wave detection (0,25 – 0,5 ms) is a necessary requirement in the engineering seismology, since duration of seismic recording seldom exceeds the value of 500 ms and the primary elastic waves are regstered in 10-20 ms after start of the recording process.
Based on these conditions, the off-line recorder should switch over into the record mode almost simultaneously with the source seismic impact. In order to detect the suitable moment of recording start, a synchronization system is used: the hammer impact forms an event in the synchronization system – the event is registered by the trigger of the seismic station. This allows to automatically start the recording process within the specified time period.
Kit for seismic research performance is a set of instruments, including mobile recorder and digital geophones interconnected with cable sections and thus forming signal line with CAN 2.0 data transfer interface. Synchronization option integrated into the CAN network enables synchronization of ZET 7155 geophones with a precision up to 10 ms (irrespective of the measuring line length and geophones amount). ZET 7175 synchronization module enables synchronization as well as timing adjustment of the geophones. This actually allows to use use several seismic streamers in a single measurements process (the seismic streamers will operate in a synchronous way).
Digital trigger ZET 7160 is used for timing of the events related to the elastic waves caused by impact hammer.