METHOD FOR DETERMINING DIFFUSION COEFFICIENT IN MASSIVE PRODUCTS OF CAPILLARY-POROUS MATERIALS Russian patent published in 2023 - IPC G01N13/00 

FIELD: measurements.

SUBSTANCE: in the test sample a uniform initial content of the solvent distributed in the solid phase is created, the upper flat surface of the sample is waterproofed, at the initial moment of time, the upper surface of the test sample is pulsed linearly moistened in a given direction of the orthotropic material along a straight line by a moving source of constant solvent productivity, the electrodes of two galvanic converters are made in the form of straight segments and placed on both sides of the pulsed humidification line on straight lines parallel to the pulsed humidification line and at different distances r1 and r2 from it, the times τ1 and τ₂ at which the same values of the signals of the first sensor E₁ and the second sensor E₂ are achieved are recorded, respectively, from the range (0.7–0.9)E_e on the descending branches of the curves of changes in the signals over time of these two sensors, and the diffusion coefficient is calculated, whereas the diffusion coefficient is measured provided that in the experiment the maximum signal E_max2 is reached, which is more distant from the line of application of the impulse action of the second galvanic sensor, equal to (0.75–0.95) E_e, and desired diffusion coefficient is calculated with the values of the signals of both sensors E₁ and E₂, approximately equal to (E_max2-0.05E_e ), where E_e is the maximum possible value of the sensor signal, corresponding to the transition of the solvent from the region associated with the solid phase of the material under study to the region of the free state.

EFFECT: improving the accuracy of measuring the diffusion coefficient of solvents in massive products made of orthotropic capillary-porous materials.

2 cl, 3 dwg