Guralp Systems CMG-3T - Manual (Page 4)

CMG-3T
The seismometer unit is self-contained apart from its 12 Volt power
supply. Centring and mass locking can be carried out by sending
control signals to the instrument, either through the hand-held control
unit or through an attached Güralp digitizer.
Each seismometer is delivered with a detailed calibration sheet
showing its serial number, measured frequency response in both the
long period and the short period sections of the seismic spectrum,
sensor DC calibration levels, and the transfer function in poles/zeros
notation.
1.1 Options
Form factors
The CMG-3T can be supplied in several forms, besides its standard
configuration:
•
The CMG-3T Compact is internally identical to the standard 3T,
but has a different arrangement of components allowing it to fit
in a smaller casing.
•
The 3T can also be supplied in a slimline form factor, with
vertically-stacked sensors, suitable for installation in post-holes
(see Section 2.5, page 18.).
•
The 3T is also available as a fully-fledged borehole instrument,
the CMG-3TB.
Any of these can be supplied with integral digitizers and data
modules, allowing the 3T to form a complete, integrated seismic
installation. For example, the 3TD is a full-height 3T with an
integrated CMG-DM24 digitiser. As an additional option, the 3TD can
be ordered with an Integrated State-of-Health Controller, which
provides the mass-control functions (normally accessed via the break-
out box) directly from controls mounted on the instrument. See
section 4.3 on page 33 for more details.
Output types
The standard 3T has a single 26-pin mil-spec waterproof connector for
signals, control and power:
4 Issue N