seismic > HVSR, VS30, vibration analysis, seismic characterization

GEMINI-2 is a compact solution for HVSR, MASW and Vibration Analysis: a single waterproof case with an integrated low frequency, high performing 3D geophone assembly (2Hz) properly coupled sensors) and a powerful true 24 bit data acquisition board with USB port for external PC. Through Gemini USB interface and the related data acquisition software, your PC becomes a perfect, high performance instrument for both data recording and post-processing analysis. Created as an instrument mainly dedicated to HVSR measurements, Gemini-2 can be used for other passive applications like vibration analysis. Completed with the appropriate accessories, it may become an active seismic acquisition system (3 channels + trigger) for MASW and "unconventional" applications. 


gemini-2 sensor

Nat. Resonance freq: 2 Hz ± 10%

Sensitivity: 2 V/cm•S-1 ± 5%

Internal resistance: 5.8 kΩ ± 5%

Damping: 0.7 ± 10%

Harmonic distortion: ≤ 0.2%

Input impedance: ≥ 10 MΩ

Operating temperature: from –25°C to +55°C

Sensor clamping: automatic when not in use

Dimensions: Diam. 128 mm h. 175mm

Weight: 2.4 Kg


data acquisition board

Power supply / Data Recording: Via USB port on an external PC (supplied by the Customer) 

Data Conversion: True 24 bit A/D Sigma-Delta converter 

Sampling rate: Max. Freq. 8ksps, simultaneously on 3+1 channels

S/N ratio: Max 117 db

Bandwidth +/- 0.1 dB: 108 Hz @ 1ksps

Bandwidth –3 dB: 212 Hz @ 1ksps

Number of channels: 3 + 1 (trigger)

Data Format: SAF (Sesame ASCII Format) / SEG2 (.dat)