Interval; Save Level - Profound VIBRA Series Manual

Again, by pressing the -key or the -key, the desired option can be selected and then activated by
pressing the -key. A detailed description of these options is given in paragraph 5.3.1 through 5.3.11.
Please note: a new setting will be saved and activated the moment you leave the Change Settings menu
and save the changes. See also paragraph 5.3.12.
5.3.1

Interval

Per interval the VIBRA saves the peak values. To change the time interval, select the option Interval with
the / -key and press the
Using the -keys, an interval of 1, 2, 3, 4, 5, 10, 15, 20, 30, 60 seconds or 2, 5, 10, 15 minutes can be
selected. Press the -key OK to confirm.
Data reduction (1/4)
This is the first of three (or four, if you purchased the VIBRA
interval option is used to specify a time interval during which the VIBRA determines the absolute maximum
vibration values. Only the maximum vibration levels, together with its date and time, will be stored in
memory. The interval time required depends on the vibration source and the type of measurement carried
out:
If the vibration nuisance during a pile-driving project has to be monitored accurately, a time interval of
2 seconds is recommended. Pile driving hammers have a blow rate of approx. 40 - 45 blows per
minute (in other words, the time interval between 2 blows is slightly more than 1 second). By
selecting a time interval of 2 seconds, one hammer blow will always be registered by the VIBRA. This
setting will provide an accurate and clear registration of the vibration nuisance caused by the pile
driving process.
If vibrations during a pile-driving project have to be measured for general monitoring only, a time
interval of 30 seconds is recommended. From the monitoring results, the number of (sheet) piles, the
start- and stop-times and the maximum vibration levels present during driving, can still be
determined. As the total installation time per foundation element takes more than 5 minutes, a time
interval of 30 seconds is advised.
5.3.2

Save Level

Select Save Level with the / -keys to set or change the "threshold" value for the data save level. Press
-key OK to confirm the selected choice. The next screen appears on the display:
-key OK. The following drop down menu appears on the display:
Manual Profound VIBRA-series, version 2.00
+
) data reduction techniques available. The
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