CMG-3T

The Güralp 3 range of compact three-component broadband seismometers are suitable for surface vault, subsurface vault, posthole and borehole installations. The instruments are thoroughly proven and have been in continuous production since 1987. The Güralp 3T is widely used on many National Seismic Networks, with over 3000 triaxial instruments deployed worldwide. The instruments can be supplied with built in digitisers, acquisition modules and a range of storage and communications options.

Model range

3T – Standard seismometer – Datasheet
3TDE – Digital seismometerr with acquisition module – Datasheet
3T Portable – Compact seismometer – Datasheet
3TB – Borehole seismometer – Datasheet

3ESPC – Compact seismometer – Datasheet
3ESPCD – Compact digital seismometer–Datasheet
3ESPCDE – Compact digital seismometerwith acquisition module –Datasheet
3EX – exploration seismometer– Datasheet

Key features / Benefits

• Force feedback broadband instrument
• Lifting handle and all connectors on the top of the instrument.
• Waterproof and durable with O-ring seals throughout
• Quick and easy, one-person installation
• Digital output and communication versions available

Typical applications

• Nuclear test ban monitoring
• Monitoring seismic activity
• Measuring the response of the ground to shaking
• Global and regional seismic networks
• Noise surveys
• CO₂ storage monitoring
• Tsunami warning
• Earthquake early warning

Example customers

• National Geophysical Research Institute, GS Canada
• Incorporated Research Institutions for Seismology (IRIS) Program for Array Seismic Studies of the Continental Lithosphere (PASSCAL)
• Kandilli Observatory Turkey and ERD

SYSTEM

Configuration / Topology: Triaxial orthogonal (ZNE)
Feedback: Force feedback

PERFORMANCE

Response: 120s – 50Hz standard (other options available)
Output sensitivity / Clip Level: 2 x 750V/ms-1 (1500V/ms-1, other options available)
Peak / Full scale output: ±10 V differential
Cross axis rejection: >65dB
Linearity: >107dB horizontal, >111dB vertical
Lowest spurious resonance: >140Hz (vertical)
Self-noise: below NLNM between 200s and 20Hz (vertical)
Dynamic range: >140dB

CALIBRATION

Type: Pulse, sine wave and broadband
Calibration controls: Independent signal & enable lines exposed on sensor connector

MASS / MASS MONITORING

Locking: Remote or automatic mass locking, unlocking and centring
Mass position output band: DC-120s
Mass recentring range: +/-2.5° from horizontal

CONTROL

Mass control / locking: Lock, unlock, centre