Hybrid Six-Component Broadband Borehole Seismometer
The AFB4.5 is ASIR's hybrid six-component borehole seismometer, combining three broadband optical interferometer accelerometers with three 4.5 Hz geophones in a single borehole instrument. This unique sensor architecture provides continuous seismic monitoring across an exceptionally wide frequency range while adding measurement redundancy for critical monitoring applications. Designed for boreholes up to 1500 m deep, the AFB4.5 is ideally suited for earthquake monitoring, induced seismicity, geothermal energy, mining, underground infrastructure, carbon storage (CCS), and scientific research. Combined with ASIR's mechanical hole-lock system, the instrument can be installed in boreholes with diameters from 95 mm to 226 mm.
Advanced Features
- hybrid optical accelerometer and geophone technology
- six-component seismic measurements
- broadband plus 4.5 Hz geophone response
- measurement redundancy for critical monitoring
- high tilt tolerance up to 15°
- for permanent or temporary installations
Application & Deployment
- On scale, 20 s to 1200 Hz bandpass, local-to-regional, M~0 to ~4, with backup 4.5 Hz seismometer
- Local and regional networks in up to 1500 m deep, <15° tilted, boreholes spaced 5 to 10 km apart
- Improves detection by 2 units of magnitude over surface nets, detecting/locating all M > ~ -0.5 EQs
- Special applications include 4 to 8 station borehole and mine networks for stimulation monitoring
Dimensions
| Outer diameter | 61 mm |
| Length | 1127 mm |
| Weight | 10 kg |
| Power requirement | 6-25 V DC |