Seismic Vibrators are truck-mounted or buggy-mounted devices that are capable of injecting low-frequency vibrations into the earth. They are one of a number of seismic sources used in Reflection Seismology.
About half of all Seismic Surveys on land are performed by using Seismic Vibrators.
A seismic vibrator transforms the energy provided by a diesel engine into a vibration. It is performed by a shaker, a movable element that generates the vibration thanks to a piston-reaction mass device driven by an Electrohydraulic Servo Valve. The shaker is applied to the ground for each vibration, then raised up so that the seismic vibrator can move to another vibrating point.
Vibrator capability is defined by the maximum force it is capable to generate, called High Peak Force and measured in pound-force. To transmit a maximum force to the ground and prevent the shaker from bumping, part of the weight of the vibrator is applied to the shaker.