The Alpha-TA120-VEL is a low noise, three component feedback, velocity output, broadband seismometer designed by Dr. C.M. Güralp. In the 1970's and 1980's Dr. Güralp, set out the standard for miniature surface and bore-hole broadband seismometers. The seismometer is based on orthogonal three axis low noise sensor modules with double nested feedback loop topology.
The mechanical suspension system is based on the principles of “elastica” and the leaf spring is deployed in a “Zero” length spring topology.
The ALPHA family of sensors are three component low noise feedback velocity output broadband seismometers, suitable for local, regional and teleseismic recording.
- Single or large scale seismic networks
- Micro-seismic monitoring
- After-shock monitoring
- Hydrocarbon exploration
- Permanent reservoir monitoring
- Induced seismicity detection
- Explosion monitoring
- Post-hole seismology
- Micro-seismic monitoring
- High quality broadband data
- Suspension system with high cross axis rejection
- Broadband data with a high frequency response extending to 150 Hz
- Automatic self-installation and zeroing for quick installation
- Tilt tolerance of ±5 degrees
- Portable and easy to deploy
- Waterproof with connectors mated
The mechanical sensor orientation is Non-Galperin with >-75 dB cross axis rejection on all axis.
The sensor frequency response of the Alpha-TA120-VEL covers the complete seismic spectrum with a flat and repeatable frequency response (No peaks) from 0.008333 Hz (120 seconds) to 150 Hz.
Optional Frequency Response VBB (Very Broad Band) sensor, Alpha-T360-Vel. Response 0.00277 Hz (360 seconds) to 150 Hz.
The sensor noise level crosses (below) the New Low Noise Model (NLNM) from 18-20 Hz to 180- 220 seconds period.
A truly portable rugged seismometer with fine pitched adjustable feet manufactured from phosphor bronze.
Remote electronic control of mass lock and unlock facility, both with serial interface and logic levels.
Two stage galvanically isolated electronic circuitry.
The sensor mechanical section and the feedback electronics sections have their own isolated and hermetically sealed enclosures.
The electronic and the mechanical sections of the sensor can be physically separated for observatory applications. This is an optional feature and the only VBB broadband sensor that can be configured to have separate mechanical and electronics sections.
Power consumption, less than 1 Watt. Operates from +9VDC to +36VDC range, with input power polarity protection.
All analogue outputs and digital inputs are transient protected.
The mechanical sensor section can be installed in a specially carved granite housing for observatory applications.