Number of geophones: 3 geophones with natural freq. 10Hz+/-5% (1 vert.+ 2 horiz.), high-sensitivity (100V/m/sec +/-5%)
Cable length: 50m or 100m, graduation in metres, mounted on cable reel with probe support
Probe dimensions: Ø51mm, length 570mm (anodised aluminium casing)
Borehole diameter: Min. 55mm, max. 110mm (with standard spacer block; larger diameters upon request)
Cable reel dimensions: 540x400x250mm
Weight: GFA-50: <12kg; GFA-100: <17kg
Seismograph connection: Standard: Cannon type NK2721C (GEA24, 16SN-U-P) or Souriau (GEA3, Anteo), Other adapters available upon request