In this paper, the eomputative formulae used to measure 2-D vibrational displacement and stress in the time-averaged method are derived. By combining the finite element method, the computation for the first-order bending vibration of a blade has been made, and the computable displacement is compared with that, measured directly by an eddying sensor. Holograms with as many as forty orders of fringes can be clearly observed, thus expanding the measurable scope of amplitude from 3λ to 10λ.