ACOUSTOELECTRONIC METHOD OF DETERMINING DISPLACEMENTS OF OBJECTS Russian patent published in 1994 - IPC

FIELD: measurement technology. SUBSTANCE: method involves the steps of: delaying a reference signal at an initial frequency by an additional small delay and recording the difference in phase of received and reference signals, excluding the additional delay of reference signal and recording the second phase difference, varying the initial frequency up to a value at which the initial phase difference of received and reference signals is recovered, finally determining displacements with regard to frequencies f₁, f₂, predetermined delay τ, propagation velocity V of surface acoustic waves. The method is characterized in that the reference signal is delay by receiving surface acoustic waves propagation over a piezoelectric plate at a fixed distance from an irradiator which is taken into account in determining displacements of an object so as to exclude the influence of environment upon surface acoustic wave propagation velocity. EFFECT: enhanced measurement accuracy due to maximum compression of ultrasonic oscillation frequency tuning range and due to excluded influence of the environment upon ultrasonic oscillation propagation velocity. 2 cl, 2 dwg