METHOD TO DETERMINE HYSTERESIS LOSSES WITH PENDULUM TRIBOMETER Russian patent published in 2015 - IPC G01N19/02 

FIELD: measurement equipment.

SUBSTANCE: coefficients of rolling friction are calculated on the basis of coefficients of hysteresis losses and radii of spots of contact of ball supports of a pendulum tribometer with tested samples. The method to determine hysteresis losses by the pendulum tribometer consists in the fact that after degreasing of surfaces of contacting bodies they couple the flat working surface of samples with ball supports of a physical pendulum, for which the initial amplitude of oscillations is set, and amplitudes of subsiding pendulum oscillations are recorded. Besides, the initial amplitude of pendulum oscillations γ₀ is selected on the basis of the condition γ₀≤0.4a/R, where a - radius of contact spot, R - radius of ball supports of the pendulum, the centre of gravity of the pendulum is matched with its supports, using amplitudes of pendulum oscillations they determine good quality of the system Q=πn/ln(γ₀/γ_n), where γ_n - amplitude after n complete oscillations, and the coefficient of hysteresis losses of the material of samples is C=π/Q.

EFFECT: reduced error of measurements due to exclusion of viscous friction against air and adhesive interaction of contacting bodies.

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