CMG-3V
1 Introduction
The CMG-3V is a single-axis seismometer contained in a sealed borehole
sonde.
The seismometer system is self-contained except for its 12 – 30 V power
supply, which is provided through the same cable as the analogue data.
Sensor functions such as levelling and mass locking are carried out
through a surface control box.
The 3V's sensor is sensitive to ground vibrations in the frequency range
0.0027 – 50 Hz, depending on the options you have specifed. It outputs
analogue voltage representing ground velocity on balanced diferential
lines. Each seismometer is delivered with a detailed calibration sheet
showing its serial number, measured frequency response in both long
and short period sections of the seismic spectrum, sensor DC calibration
levels, and the transfer function in poles/zeros notation.
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