Patent ID: 8664828

Claim:
An apparatus for testing a piezoelectric/electrostrictive actuator, wherein the apparatus is provided with means for estimating the displacement of the piezoelectric/electrostrictive actuator on the basis of the relation between one or more frequency characteristic values selected from the group consisting of (1) the heights and areas of the peaks of the resonance waveforms and (2) the difference of the maximum and minimum of the first order or first to higher orders of the resonance frequency characteristic values of the piezoelectric/electrostrictive actuator and the k-th order (k=1 to 4) of the first or first to higher orders of resonance frequencies, wherein the relation is a relation of dividing the one or more frequency characteristic values selected from the group consisting of the heights and areas of the peaks of the resonance waveforms and the difference of the maximum and minimum of the first order of the resonance frequency characteristic values of the piezoelectric/electrostrictive actuator by the k-th order (k=1 to 4) of the first order of resonance frequency, and wherein the apparatus is provided with means for estimating the displacement of the piezoelectric/electrostrictive actuator by the calculated value obtained by the division.