Abstract
Recently, there is a high expectation for viscometer to measure polymeric solutions, adhesive agents, coating materials, abrasives, and so on. Vibration-type viscometer is known as a sensor to be able to measure time variation of the viscosity with change of the material characteristics. However, conventional vibration-type viscometer uses Quality factor of frequency response curve under external excitation, and requires the observation of the frequency response curve near the resonance peak. In this research, to overcome the drawback, we theoretically proposed a viscometer based on self-excited oscillation under positive linear feedback. The critical feedback gain which produces the self-excited oscillation corresponds to the viscosity. Also, from experimental results, the validity of the proposed method is discussed.
