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.
Specifications
| SENSOR GEMINI-2 |
| 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 d |
212 Hz @ 1ksps |
| Number of channels |
3 + 1 (trigger) |
| Data Format |
SAF (Sesame ASCII Format) / SEG2 (.dat) |
