Guralp Systems CMG-40TDE - Manual (Page 5)

Operator's Guide
The integrated digitiser is a CMG-DM24, a low-noise, 24-bit ADC
module specifically designed for seismic data. The built-in digital
signal processor (DSP) provides simultaneous, multiple sample-rate
data streams at user-selectable rates. Up to 6 streams of data for each
component are available at sample rates from 1 to 1000 samples/s. A
precision microprocessor-controlled time-base synchronizes the
analogue-to-digital converters to the DSP and provides time-stamps for
data. A separate microprocessor system handles configuration and
sensor control, including mass centring and calibration.
The integrated data acquisition system is a CMG-EAM,
which provides serial and Ethernet communications, along with a
convenient web-based interface to all functions, including digitiser
and sensor configuration and control. It can act as a data recorder as
well as a protocol converter and communications controller. Based
around the powerful and stable Linux operating system, the CMG-
EAM offers unrivalled flexibility, even including the ability to run
user-installed scripts.
Each instrument 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.
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