Abstract: Piezoelectric plates conduct bending vibrations and are axially symmetrical about the vibration shaft so the piezoelectric plates conduct a bending vibration, lower vibrating ends of the piezoelectric plates are rigidly connected to a vibration suppressing member and upper vibration ends of the piezoelectric plates are rigidly connected to the vibration shaft, an inner edge of each of the piezoelectric plates excluding the vibration connection part is free of the vibration shaft, a bending vibration at the lower vibrating end of each of the piezoelectric plates is suppressed on the vibration suppression connection part side and a bending vibration at the upper vibrating end is amplified and then applied to the vibration shaft and the liquid detecting element which is disposed at a lower end of the vibration shaft, through the vibration connection part, so that the liquid detecting element is vibrated in the circular direction in the measuring liquid.

Abstract: A method for measuring viscosity of liquid, in which a liquid detecting piece 3 is vibrated by a vibrator 1, vibration of the liquid detecting piece 3 in liquid 4 is detected, and viscosity of the liquid 4 is measured from vibration thus obtained, the method comprising the steps of detecting frequency and amplitude which are variable attributable to liquid-specific visco-elasticity from the vibration, obtaining impedance of the liquid from the frequency and the amplitude, and obtaining a dynamic viscosity from a real number part and an imaginary number part of the impedance. There is also disclosed a method for measuring visco-elasticity of liquid comprising the step of obtaining a dynamic viscosity, a dynamic elasticity and a static elasticity of the liquid from a real number part and an imaginary number part of the impedance.