DownHole > Work theory > Experimental procedure

The source consists of an aluminum plate that, after the ground plane is prepared, is placed so that the plate is lying on the surface at a distance of 1,5 to 2,5 m from the hole and oriented in the direction orthogonal to the outgoing axis within the hole.

At the source is hooked the speed sensor used as a trigger. If you have two receivers, these are connected so as to prevent relative rotation and to set the distance. The first of the two receivers is connected to a rod (ground) battery that allows the orientation from the surface and the moving. Once at the test depth, the geophones are oriented so that each sensor is a transducer, parallel to the axis of source (absolute orientation). At this point, the receivers are secured to the walls of pipe coating, the source will be affected in the vertical direction (to generate waves compression P) or laterally (to generate shear waves SH) and, simultaneously start the registration of trigger signal and receivers.

Once the registrations are recorded, the depth of the receivers is changed and the test procedure repeated.