The quasi-static method is based on the direct piezoelectric effect . The piezoelctric sample is evenlyloaded with the force F. The charge is generated when the amout of force on the electrode of the piezoelctric sample change . The measurement set- up is shown in 6 . The change of force Is attained by a weight placed on the side of the lever. On instant unloading of the wieght and after amplifying of the charge in an AURA ( type C4 .2) or (bbb ) charege amplifier,a voltage pulse equivalent to the applied force is measured on the Agilent DSO3062A oscilloscope from the force F and voltage U, and is consistant with the charge of force F. (8)(14)