GURALP CMG-6T - Sismic

Specification
GURALP CMG-6T
BROADBAND SEISMOMETER
Capacitive displacement feedback
Three-component differential velocity outputs
Short-period response to 50 Hz
Long-period response to 1, 10, 30, or 60 sec
Mass clamp not required
Mass centering not required
DC-offset adjustment icluded
" Breakout Box and Handheld Control Unit
available
" A 24-bit digitizer module (CMG-DM24) and
a portable storage/acquisition module (CMG-
SAM) are available
The Guralp CMG-6T three-component
broadband seismometer provides high dynamic
range broadband velocity response for a variety
of applications.
The standard frequency band is 30 sec to 50 Hz.
While the CMG-6 noise floor is higher than that
of the CMG-3ESP and CMG-3T sensors, the
moderate price makes the instrument an
attractive selection for several applications:
" Portable and rapid array mobilizations in
which reliability, low power, and installation
simplicity are important
" Permanent installation at sites which do not
have seismic background close to the USGS
Low Noise Model
" Short to medium term installations in which
vault temperature and tilt are not as well
controlled as for permanant sites
Distributor: Digital Technology Associates, Inc.
1330-A Galaxy Way, Concord, CA 94520 USA
Tel: (925) 682-2508 Fax: (925) 682-2072
dta_pauly@compuserve.com
Manufacturer: Guralp Systems Limited, 3 Midas House
Calleva Park, Aldermaston, RG7 8EA, England
Tel: 44-118-9819056 Fax: 44-118-9819943
sales@guralp.com
www.guralp.com
10 Feb 01
Page 1
CMG-6T

CMG-6T SPECIFICATIONS
Outputs and Response
Standard velocity output:
Optional high-gain output:
Standard frequency band:
Optional frequency bands:
Peak output:
Clip level and self noise:
20 V dc differential velocity = 2x2000 V/m/s for 30 sec sensor
10 Vdc mass position output = 20 V/m/s2 for 30 sec sensor
8000 V/m/s
0.033 (30 sec) to 50 Hz
0.100 (10 sec) to 50 Hz
0.016 (60 sec) to 50 Hz
±10 V (20 V p-p) standard
±4.5 V (9 V p-p) optional
See figure on page 1. The chart noise levels are peak-to-peak
estimates, in m/s2, equal to six times the measured RMS acceleration
values for a 1/3 octave bandwidth. The USGS Low Noise Model (LNM)
is a composite from the best stations in the world at their quietest. The
High Noise Model (HNM) represents the noisy sites at their best.
Controls
External calibration enable & input: Directly to the sensor connector
DC null adjustment:
Screw adjustment thru case
Optional remote DC adjustment: Remote operation via dc motors
Power THREE COMPONENTS SINGLE COMPONENT
For standard (10 V) output: ±26 mA @ ±12 Vdc or
+65 mA @ +12 Vdc
For optional (4.5 V) output: +20 mA @ +5 Vdc
For 60 sec output add:
22 mA @ +12 Vdc
Physical
Case diameter: 6.625”
Case height: 8”
O-ring seals:
In lid, base, and portholes
Carrying handle:
On top cap
Cable connection:
Multipin connector on top cap
Lowest spurious resonance: 400Hz
Operating temperature range: -10 to +65 deg C
Temperature sensitivity:
< 0.6 V/10 deg C
Pressure jacket & cap material: Aluminum
Weight:
18lbs (6 kg)
Single-component Specifications (models CMG-6V and CMG-6H)
Case diameter and height: 3.25” diameter, 6.5" height
Cable:
Glass-sealed in base, 1m with connector
Weight:
3 lbs
Options, Accessories, & Reference Data
Refer to separate document for Handheld Control Unit, Passcal UniversalBreakout Box, and sensor noise
information. Refer to separate documents for digitizer and storage module information.
Downhole Accessories
Refer to separate brochure, ‘Guralp Broadband Downhole Systems’
Distributor: Digital Technology Associates, Inc.
1330-A Galaxy Way, Concord, CA 94520 USA
Tel: (925) 682-2508 Fax: (925) 682-2072
dta_pauly@compuserve.com
Manufacturer: Guralp Systems Limited, 3 Midas House
Calleva Park, Aldermaston, RG7 8EA, England
Tel: 44-118-9819056 Fax: 44-118-9819943
sales@guralp.com
www.guralp.com
10 Feb 01
Page 1
CMG-6T