Enquiry:hkmarketing@epc.com.hk 
The borehole geophone BGK series is used to receive P- and S-waves in dry or water lled boreholes. e borehole geophone BGK3 consists of a tri-axial sensor whereas the BGK7 consists of six horizontal sensors, separated by 30° intervals, and one vertical sensor. The geophone is coupled to the borehole wall by a pneumatic clamping system (inatable bladder). Air is supplied to the BGK through an electro-pneumatic hybrid cable with a Kevlar tension string. A magnetic compass shows azimuthal deviation to North and can be used to get the orientation of the geophone in the borehole. e cable is terminated by a connector to the seismograph.
Natural sensor frequency: 30 Hz (others on request) Sensor arrangement: Tri-axial (BGK3) or 6 horizontal (30°)/1 vertical (BGK7) Operational depth: Up to 100 m Receiver length: 705 mm Receiver diameter: 50 mm Receiver weight: 3 kg Cable weight per metre: 145 g Cable strength: 2150 N Borehole diameter: 75 mm (or larger if spacers are used) Clamping system: Inatable bladder Orientation: Magnetic compass (+/-2.5°) Depth indicator: Cable marking every 2 m Connector: To any seismograph Storage: On drum
