Patent ID: 8215156

Claim:
A method for measuring viscosity and elasticity of a liquid by immersing and vibrating a liquid tester in the liquid to be tested, the method comprising: measuring three frequency values that are a resonance frequency value (f 0 ) on an amplitude characteristic curve obtained through vibration of the liquid tester in the liquid being tested, a low frequency value (f 1 ) lower than the resonance frequency value (f 0 ) on the amplitude characteristic curve at a phase angle smaller than a phase angle of 90 degrees at a resonance point on a phase angle characteristic curve obtained through the vibration in the liquid being tested, and a high frequency value (f 2 ) higher than the resonance frequency value (f 0 ) on the amplitude characteristic curve at a phase angle larger than the phase angle at the resonance point on the phase angle characteristic curve; calculating a real part of impedance of the liquid being tested using the high frequency value (f 2 ) and the low frequency value (f 1 ); calculating an imaginary part of the impedance of the liquid being tested using the resonance frequency value (f 0 ); and calculating the viscosity value and the elasticity value of the liquid being tested from the real part and the imaginary part of the impedance.