Mini-Seis III Pro™ Operating Manual
Page 23
Mode Screen Functions (Waveform Mode)
Waveform Mode is most often used for monitoring transient vibration sources like blasting.
However, it is also appropriate for other vibration sources where capturing the time history
is desired. For continuous or semi-continuous vibration sources, the Histogram/Waveform
Mode may be a better selection.
Waveform Mode utilizes trigger thresholds for ground vibration and air overpressure. If
either of these thresholds are met or exceeded, the instrument will activate and record for a
specified duration at a fixed sample rate. There is a pre-trigger buffer of 1024 samples.
Thus, the pre-trigger duration varies proportional to the sample rate. For example, a 2048
sample rate has a pre-trigger of 0.5 second.
Waveform
Rate: 1024 /SEC
Duration: 8 SEC
Seismic Trig: 0.05000 IPS
Acoustic Trig:: 125 dB
Rate
The sample rate is selectable at 1024, 2048, 4096, 8192 or 16384 over 4 or 8 channels of data.
Single channel rates of 64K or 128K are also available. To change the rate, select the field
and use the left or right arrow key.
Duration
The duration is the amount of time the unit will actively record after receiving a trigger. This
time does not include the pre-trigger. The duration can be from 1 to 120 seconds. To
change the duration, select the field and use either the left or right arrow key.
Note: In general, the higher the sample rate and the longer the
duration, the larger the record size.
Seismic Trigger
This is the trigger threshold at which the unit will trigger from a ground vibration. To set the
value, highlight the field and use the left or right arrow key. Holding the keys down will
change the value at a faster rate.
The trigger resolution is based on the maximum range of the seismograph. The standard
minimum trigger starts at 0.01 in/s (0.254 mm/s) and can be increased in steps of 0.005 ins
(0.127 mm/s) based on a maximum range of 10.24 in/s (260 mm/s).
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