Foundtest (M) Sdn Bhd is a professional engineering firm
which specializes in construction testing services including
Vibration Monitoring. The firm utilizes the VIBRA-a,
which is FPDA (Foundation Pile Diagnostic Systems) series and
software which is specially designed for ground and structural
vibration monitoring.
Vibration Monitoring is used to monitor and record vibrations caused
by pile driving, traffic, machinery, explosions or other vibration
sources. Vibration sensors, placed on the ground or connected to a
structure, can be monitored simultaneously. Continuous recording or
even triggering mode can be selected during the monitoring process.
The VIBRA-a consist of 3
vibration transducers (geophones) and a data acquisition computer
with LCD display. It measures, displays and stores the peak values
of the vibrations.
Reliable performance over time in an environment with moisture, dirt
and vibrations, demands much of the applied measuring system.
Therefore the microcomputer is located in a watertight robust
housing and is powered by an internal rechargeable battery or
external power. Data from the memory may be transferred to a PC.
The measurement results are presented on an LCD screen with clear
readable characters and digits.
The
standard vibration transducers used for VIBRA-a
are velocity transducers (geophones). A Standard 3-D X, Y, Z
sensors is supplied. The sensors have a robust polyester case. For
correct measuring, the sensor should be leveled accurately (use the
circular bubble). The axes of the horizontal components are
indicated on the case top.
|
Channel |
Direction |
|
1 |
Vertical |
|
2 |
Horizontal (Long Arrow Direction) |
|
3 |
Horizontal (Short Arrow Direction) |
The
vibration transducers are to be mounted to the structure where the
vibrations are to be measured. In most cases a mounting based on
gravity is sufficient. The transducers for the vertical and
horizontal direction cannot be interchanged. A transducer for the
vertical direction will not measure any vibrations in horizontal
direction and visa versa.
When
the vibration transducers are placed on site and the cable is
connected to the transducers and VIBRA-a,
the vibration measurements can be started. The VIBRA-a
will display the results of the vibration peak value of velocity of
vibration.
The
time period over which the peak value of the vibration signals is
stored can be adjusted with TIMEBASE button. All of the measured
values are stored in memory. Data from the memory can be
transferred to the PC for result interpretation and report
preparation
