ADDITIVE METHOD AND DEVICE FOR EXTERNAL EXCITATION OF MECHANICAL OSCILLATORY SYSTEM OF VIBRO-VISCOMETER Russian patent published in 2020 - IPC G01N29/00 

FIELD: physics.

SUBSTANCE: invention relates to investigation of fluid properties using vibro-viscosimeters. Essence: oscillatory system is brought into mode of oscillations by means of excitation device, frequency of oscillations of excitation device is continuously changed to achieve natural frequency ω₀, which is determined after achieving a preset at each frequency in the operating frequency range of the phase shift between oscillations of the excitation device and oscillations of the output amplified and frequency-filtered position sensor signal and stored in the microcontroller memory, periodically varying the active rigidity of the oscillating system by a known value by adding to the exciting excitation device signal a known portion of the output signal of the probe position sensor, and new values of intrinsic frequency of oscillation system ω_0m are determined, and by values of frequencies ω₀ and ω_0m by calculation method current operating values of oscillating mass m_L and stiffness coefficient k_L of oscillatory system are determined by formulas. Device comprises device vibration excitation vibrating vibro-viscometer, recording and control device based on microcontroller, in memory of which is recorded control program for excitation device and frequency-phase characteristic of frequency-filtering circuit, sensor of probe position, which output is connected to input of electronic amplifier, which output is connected to input of frequency-filtering circuit, two-input adder with switch on second input, first input of adder is connected to output of excitation device, output of electronic amplifier is also connected to second input of adder through switch, control input of which is connected to one of control outputs of device for registration and control of vibro-viscometer.

EFFECT: high accuracy of determining the parameters of the analysed liquid, measured by the vibro-viscometer, by additional determination with allowance for the elastic properties of the liquid, dynamic parameters of the mechanical vibration system of the vibro-viscometer.

2 cl, 1 dwg