2.5-3Hz Geophone
China Geo-Equipment Corporation [China] 
2.5Hz-3Hz vertical,horizontal and tri-conponents geophone.
CDJ low-frequency geophones, 1Hz, 2Hz, 2.5Hz or 3Hz, are widely used in deep seismic prospecting, earthquake monitoring, microseismometry in engineering, surface wave survey and low frequency measurement in other fields.
SPECIFICATIONS
| CDJ-Z2.5C | CDJ-P2.5C | CDJ-S2.5C | CDJ-Z3C | CDJ-P3C | CDJ-S3C | |
Vertical | Horizontal | 3-C | Vertical | Horizontal | 3-C | |
| Nature Frequency Fn (Hz) | 2.5±10% | 2±10% | ||||
| Sensitivity in Open Circuit G (v/cm/s) | ||||||
| Sensitivity in Shunt G (v/cm/s) | 2±10% | 2±10% | ||||
| Damp in Open Circuit Bt | ||||||
| Damp in Shunt Bt | 0.7±10% | 0.7±10% | ||||
| Coil Resistance Rc (Ω) | 6040±10% | 6040±5% | ||||
| Resistance R (Ω) | 5650±10% | 5500±5% | ||||
| Insulation Resistance R (MΩ) | ≥20 | ≥20 | ||||
| Harmonic Distortion D (%) | ≤0.2 | ≤0.2 | ||||
| Coil to Case Movement P-P (mm) | 3 | 3 | ||||
| Suspended Mass M (g) | 60 | 60 | ||||
| Operating Temperature (°C) | -25~+55 | -25~+55 | ||||
| Coil diameter (mm) | Ø38.5 | Ø38.5 | ||||
| Coil Height (mm) | 47 | 47 | ||||
| Coil Weight (mm) | 0.25 | 0.25 | ||||
| Case Diameter (mm) | 55x70 | 55x70 | 128 | 55x70 | 55x70 | 128 |
| Case Height (mm) | 87 | 80 | 134 | 87 | 80 | 134 |
| Weight (g) | 0.48 | 0.48 | 2.35 | 0.48 | 0.48 | 2.35 |
2.5-3Hz Geophone
