METHOD OF DETERMINATION OF LIQUID SURFACE TENSION BY CAPILLARY METHOD Russian patent published in 2015 - IPC G01N13/02 

FIELD: instrumentation.

SUBSTANCE: invention is intended for positive determination of surface tension factor of the liquids σ₂₁, factor σ₂₁ means liquid (2) surface tension at its border with steam (1) or other gas. Method of determination of the surface tension factor of liquids includes measurement of exceedance of liquid equilibrium level in capillary above water level in wide vessel during lifting and during outflow. At that measurement of exceedance of the equilibrium level of liquid in capillary above the liquid level in wide vessel during lifting and outflow is performed several times without complete capillary removal from liquid. Further the surface tension factor is determined as per equation: 4h₁σ₂₁ = ρgrh₁ ²+2h₁h₂ρgr-ρgr₀ ²h₂, where h₁ is average exceedance of equilibrium level of liquid in capillary during its lifting; h₂ is average exceedance of equilibrium level of liquid in capillary during its outflow; ρ is liquid density; r is capillary radius; r₀ is capillarity radius of system "capillary material - liquid".

EFFECT: positive determination of the surface tension factor of liquid by the capillary method.