The Mini-Geophone M40 consist of 2 horizontally polarized receiver elements and a vertical one. The borehole geophone is pneumatically clamped to the wall by means of a robust air bladder. It is connected to a rotary string which is inflexible regarding turning the string in radial direction but can easily be coiled up in axial direction. Stiffness of the rotary string enables the system to be pushed also in horizontal boreholes and allows easy orientation by turning the rotary string.
The small outer diameter of about 40 mm makes the M40 an ideal device for investigation in small drilling holes.
Application at the tunnel wall
Specifications
Receiver elements: Accelerometers or geophones
Frequency response: 10 - 10000 Hz or other
Tool diameter: approx 40 mm
Tool length: approx 350 mm
Housing: Stainless steel
Clamping: Air Bladder
Applicable borehole size: 50 mm
Accessories
Cable 10 m long (other on request)
Surface display unit with connector to seismograph and air supply
