Guralp Systems CMG-3ESPC - Manual

CMG-3ESPC
Seismometer
Installation
Loosen the brass locking nut on one of the adjustable
feet, then turn the foot, screwing it in or out to level the
sensor. Check using the spirit level on the sensor lid.
Repeat with the other adjustable foot, until the bubble in
the spirit level lies entirely within the inner circle.
Tighten the brass locking nuts downwards to secure the
feet.
3
Choose a suitable site to install the sensor.
The sensor should be mounted:
• at, or ideally below, ground level;
• away from sources of natural noise (e.g. wind, surf);
• away from sources of cultural noise (e.g. traffic);
• in contact with bedrock or, if that is not possible, on a
hard granite or concrete pier;
• in an environment with constant temperature;
• shielded from air currents (e.g. in a polystyrene box)
• away from electrical cables and appliances.
2
4
If you are using a breakout box, connect the signal cable
between the sensor and the SENSOR connector of the
breakout box, and connect the POWER connector to your
12 V power supply.
Hold down the ENABLE button on the side of the box,
and press the UNLOCK button for a few seconds. The
BUSY LED will light, and you should be able to hear the
internal motors unlocking the masses. CENTRE the
masses if necessary.
See the full manual for detailed usage instructions.
Check you have all components and cables:
• CMG-3ESP Compact weak motion broadband
seismometer;
• Thick grey signal cable;
• Sensor calibration data booklet.
You will need a suitable digitizer or recording equipment,
and a 12–24 V DC power supply.
For pit or posthole installations, follow the steps
overleaf.
1