MBAS: Multistation Borehole Acquisition System

The Multistation Borehole Acquisition System (MBAS) is a digital three-component geophone string used to receive P- and S-waves in dry or water filled boreholes. Up to ten individual stations with tri-axial sensors can be connected. The stations are aligned to ensure that all horizontal sensors are oriented in same direction. The system can be oriented from the surface by a torsionally stiff hose. Each station is clamped to the borehole wall by two pneumatic cylinders. An external trigger can be plugged into the USB interface on surface which is connected to a laptop. The operation is entirely controlled by the acquisition software. A separate seismograph is not required.

The orientation of the geophone stations can be aligned from the surface by means of a rotational hose. The trigger is plugged into a USB interface which connects the data line of the MBAS to a prtable PC.

Natural sensor frequency: 30 Hz (others on request)

Sensor arrangement: Tri-axial 

Operational depth: Up to 100 m

Max. number of stations: 10

Station interval: 1 or 2 m

Station length: 735 mm

Station diameter: 65 mm

Station weight: 2.5 kg

Cable weight per meter: 460 g

Borehole diameter: 75 mm

Clamping system: Pneumatic cylinders

Orientation: Torsionally stiff hose

Depth indicator: Cable marking every 2 m

Storage:  Cable on drum, geophone stations in boxes

Design: Micromed

Power supply: PC USB interface

A/D conversion: 24 bit

Sampling frequencies:  256, 512, 1024, 2048, 4096, 8192, 16384, 32768 Hz

Trace length: Max. 4 s

Trigger: TTL, geophone

Software: Soilspy (Micromed)