Description
Borehole 3D Geophone Mod. GFA 50/100 is designed for seismic borehole testing according to ASTM D7400-08 (downhole) and ASTM D4428 (crosshole). It is based on 3x high-sensitivity sensor elements (nat.freq.10 Hz – 1 vertical and 2 horizontal sensors), oriented according to a triad of orthogonal Cartesian axes XYZ. Supplied with a cleat assembly to sustain its weight at the requested depth (GFA cable is graduated in meters), this borehole geophone has a pneumatic-mechanical clamping system with lateral lever and spacer block.
Simply connect the pump to the GFA panel to operate: pumping air at a pressure of 2-3 bar, you will achieve excellent sensor coupling to the borehole wall (diameter between 50 and 110mm for use with the standard spacers). GFA is lightweight and easy to transport; the anodised aluminium casing makes it suitable for use on-site and easy to maintain. Moreover, two GFA can be connected one under the other by means of a special spacer accessory. Available in two versions: GFA-50 with 50m of cable and GFA-100 with 100m of cable.
Standard equipment includes:
- Cable reel with probe (GFA-50 with 50m cable, GFA-100 with 100m cable)
- Nose piece for drilling muds
- Manual Pump
- Cleat Assembly
- Connecting cable for seismograph
