MidLine 15 Hz Borehole Geophone – Omni-Directional

The AF15 is ASIR's high-sensitivity three-component 15 Hz borehole geophone designed for deep borehole seismic monitoring in demanding environments. Its omni-directional sensor design eliminates tilt restrictions during installation, while optional high-temperature geophone elements allow reliable operation at temperatures up to +100 °C. Optimized for boreholes up to 3000 m deep, the AF15 provides exceptional sensitivity and long-term stability for mining, geothermal energy, induced seismicity, underground infrastructure, and scientific research applications. When combined with ASIR's mechanical hole-lock system, it can be installed in boreholes with diameters ranging from 95 mm to 226 mm.

Advanced Features

• slim 61 mm outer diameter (OD)
• passive geophone sensors
• omni-directional
• for permanent or temporary installations

Application & Deployment

• Deep borehole seismograph for seismicity detection: 1 station for statistics, 4 to 6 for earthquake locations
• Deployed in any tilt, 1,000 to 3,000 m boreholes, spaced ~3 to ~6 km apart for ~ 25 to 250 m event location accuracy
• Improves detection by 2 to 3 magnitude units over surface stations, covering all M ~ -1.5 within ~3 km radius

Dimensions

Outer diameter	61 mm (without fins)
Length	1020 mm
Weight	10 kg
Power requirement	-