Hydraulic RC circuit-based viscometer and corresponding method for measuring the viscosity of a fluid

Abstract

The invention relates to a fluid viscosity sensor comprising: - an entrance (E1 ) for the fluid at initial pressure (P1 ), - at least one input hydraulic resistance (R1), - at least one hydraulic capacitance (C), - the input hydraulic resistance (R1) being followed by the hydraulic capacitance (C), - preferably at least one output hydraulic resistance (R2) sequentially placed after the elastic hydraulic capacitance (C), - an output (E2) for the fluid, - at least two pressure sensing elements (PS1, PS2), preferably three pressure sensing elements (PS1, PS2, PS3), - a processing device (PD) configured to calculate, when a liquid flow is laminar, a time constant of the viscosity sensor, T [S], from a temporal variation of the pressure signals from the pressure sensing elements and use said time constant to estimate the viscosity p of the fluid flowing through the sensor following the formula μ=τ (R1,g + R2,g) / (R1gR2,gC) [Pa.s], R1g being equal to the geometrical terms of the input hydraulic resistance (R1) and R2g being equal to the geometrical terms of the output hydraulic resistance (R2).

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