ABEM Terraloc Pro 2
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increased, the result is of course an earlier trig event, but increasing
the sensitivity also means that the risk of triggering the system by a
noise signal increases. If the sensitivity is too low, noise triggering
will not occur, but instead a considerable and poorly defined delay
is introduced. This can seriously degrade the performance of the
stacking of signals, since any signal with a period time comparable
to, or less than this trig event uncertainty, will be attenuated. So in
conclusion, you will have to find a suitable compromise between
high sensitivity to false triggering and large timing errors.
Warn for
noisy trig
-
The meaning is to warn when there is a risk that sampling was
triggered on noise instead of signal level. A possible warning is
shown in the status bar (see chapter 4.4.7). This setting, together
with its three sub settings (below), decides how the evaluation is
done. If the signal level is higher than the given level in connection
with the trigger point then the warning is raised. Figure 44
illustrates the meaning of the involved settings.
Figure 44 Trig signal from a geophone and the trig event
Evaluation
time [ms]
-
The time window during which the signal level is checked against
the
Noise warning level
. See Figure 44 above
Guard time
[ms]
-
A time window where the signal level is not checked. This is to
avoid false warnings from the time just before the trig point. See
Figure 44 above
Noise
warning
level [%]
-
The threshold level for the noise warning. See Figure 44 above
Warn for
early trig
-
The meaning is to warn when there is a risk that sampling was
triggered before a stable measurement was possible. A possible
warning is shown in the status bar (see chapter 4.4.7).
Table 9 Trig settings
