Guralp Systems CMG-5T Compact - Manual (Page 8)

CMG-5T Compact
insulation slabs) with the
joints between them sealed.
A hole should be drilled for
the connector. You can then
use high-grade glass fibre
sealing tape to fix the leads in
position and to fasten the box
securely to the mounting
surface.
Commercially
available duct sealing tape is
ideal for this purpose.
6. Connect the sensor to your digitizing equipment or Hand-held
Control Unit to start receiving signals.
2.3.1 Temporary installations
5T Compact sensors are ideal for monitoring vibrations at field sites,
owing to their ruggedness, high sensitivity and ease of deployment.
Temporary installations will usually be in hand-dug pits or machine-
augered holes. Once a level base is made in the floor, the
accelerometer can be sited there and covered with a box or bucket.
One way to produce a level base is to use a hard-setting liquid:
1. Prepare a quick-setting cement/sand mixture and pour it into the
hole.
2. “Puddle” the cement by vibrating it until it is fully liquefied,
allowing its surface to level out.
3. Depending on the temperature and type of cement used, the
mixture will set over the next 2 to 12 hours.
4. Install the sensor as above, then cover and back-fill the
emplacement with soil, sand, or polystyrene beads.
5. Cover the hole with a turf-capped board to exclude wind noise
and to provide a stable thermal environment.
If you prefer, you can use quicker-setting plaster or polyester mixtures
to provide a mounting surface. However, you must take care to
prevent the liquid leaking away by “proofing” the hole beforehand.
Dental plaster, or similar mixtures, may need reinforcing with sacking
or muslin.
2.3.2 Installation in Hazardous environments
The fully enclosed, aluminium case design of the 5T Compact
8 Issue E