PURPOSE: To strickly regulate the condition of striking by using a system in which a mover and a rotor electrode are attached to each of a weight and a guide bar, and linear motor to drive the weight along the guide bar and a controller therefor are provided.

CONSTITUTION: A guide bar 2 is supported vertically by the upper supporting portion 10a of a supporter 10. The guide bar 2 is thrust with a weight 1 in such a way as to temporarily couple the supporter 2 with the weight 1. A hole 11a for a nest 11 is drilled in the lower end of the guide bar 2 for setting a penetration tester in it. Then, various kinds of detectors 7 are set, and a controller 6 is adjusted so that the weight 1 is driven along the guide bar according to a given condition. The weight 1 is driven by the controller 6 according to a given condition to strike the upper part of the nest 11, whereby the weight 1 is controlled according to various conditions and proper data are obtained.