66--SILICON AUDIO BOREHOLE SENSORS

Silicon Audio Low-Noise Optical Seismic Sensor Silicon Audio integrated the mechanics of conventional geophones with innovative optical technologies to create a scientific-grade seismic sensor with unparalleled characteristics and performance for resource exploration and scientific discovery. The sensor delivers superior signal-to-noise ratio and broadband response in a rugged, easy-to-deploy form factor. Developed originally for ocean-bottom exploration, the sensor has been deployed around the world in a wide variety of seismic applications and is available in various packaging configurations. With the largest dynamic range available among seismic sensors, the Silicon Audio sensor eliminates the need for multiple sensors to maximize the signal capture in terms of seismic amplitude and bandwidth. For example, applications which once required a broad-band seismometer paired with a strong-motion accelerometer can be addressed with a single Silicon Audio sensor. Performance Attributes: • Ultra-low noise and low frequency. • High shock tolerance. • Wide bandwidth and dynamic range. • Bridges weak- and strong-motion applications. • Low cross-axis sensitivity. • Low power design. • Very large tilt tolerance. • High clip levels and low distortion levels. • High linearity across full bandwidth. • High vector fidelity. • Small, lightweight, rugged form factor. • Customizable packaging/configuration Model 203-60 (High Sensitivity) Borehole Sensor Specifications Sensor Performance Passband • 0.005 – 1500 Hz Noise • 0.5 ng/√Hz at 10 Hz • 0.8 ng/√Hz at 1 Hz • 3 ng/√Hz at 0.1 Hz • 10 ng/√Hz at 0.01 Hz Clip Level • ±0.5 g peak -- 1 of 3 -- Dynamic Range (at 1 Hz over 1 Hz BW) • 172 dB Sensitivity • 60 V/g Max Vout • 60 V pk-pk Spurious Resonance • > 600 Hz Tilt Tolerance • ±15° (higher tilts available up to 180°) Distortion • < 0.03% at 12 Hz and 0.7 in/s pk-pk Power Power Consumption • 150 mW for 3-axis sensor (as low as 80 mW with reduced clip level) Supply Voltage • 6–25 V DC Handling Transport • No mass lock required for transport Shock Tolerance • > 1500 g (0.5 ms ½-sine) Operating Temperature • –35 °C to +75 °C (polar-rated sensors available) General Dimensions • Borehole package: 2.0" Diameter × 14.5" Length (51 mm D × 368 mm L) — Mass: 1 kg -- 2 of 3 -- Configuration • 3-axis Sensing Method • Force balance with interferometric transducer Mass Centering • Automatic -- 3 of 3 --