BHC4: Hydrophone String

The hydrophone string BHC4 is used to receive P-waves in water filled boreholes. The BHC4 consists of a downhole cable containing a Kevlar tension string and a number of moulded hydrophones at pre-defined intervals. Each hydrophone consists of a sensor with a pre-amplification board. The electronic boards are powered from the surface by a bank of rechargeable AA cells. The cable is terminated by a connector to the seismograph. 

The standard cable length is 123 m with a hydrophone spacing of 1m (other on request).

Hydrophone sensor: SQ54 or AQ2000

Frequency response: Flat from 1 to 10.000 Hz

Pre-Amplification: 4 or 10 x

Power supply: AA cells (battery box on surface)

Operational depth:  Up to 500 m

Number of hydrophones: 24 (others on request)

Hydrophone interval: 1 m (others on request)

Hydrophone diameter: 38 mm

Cable weight per metre: 200 g

Cable strength: 4700 N

Borehole diameter: Min. 50 mm

Depth indicator: Cable marking every 2 m

Connector: To any seismograph

Storage: On drum