Guralp Systems CMG-40T - Manual (Page 13)

Operator's guide
6. Attach a Handheld Control Unit and adapter cable to the ribbon
connector, and power up the sensor through the control unit.
7. Set the CENTRING SELECT switch on the Handheld Control Unit to 1
SEC VEL, and the monitoring dial to V MASS POS.
8. There are three holes in the topmost electronics board, which provide
access to the offset potentiometers. Insert a screwdriver through the
appropriate hole, and engage the potentiometer for the vertical
component.
9. Adjust the potentiometer until the mass position output reads close to
zero.
10.Repeat steps 4 – 6 for the north/south and east/west components.
Alternatively, you can adjust the mass postions and monitor the output digitally.
1. Remove the vent cap, and use an Allen key to remove the screws
holding the digitizer module onto the sensor as above.
2. Carefully lift off the digitizer module, and support it nearby, leaving the
ribbon cable connected. Extension cables can be obtained from Güralp
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