There is proposed a device for control of liquids surface properties which implements the external meniscus method. There are described the standard uncertainties of the input variables affecting the liquids surface properties measurement by proposed device. These uncertainties are divided into two groups - the uncertainties of proposed device and the uncertainties of external meniscus method. There is proposed the procedure of external meniscus method uncertainty calculating. Special attention is paid to the uncertainty calculation of theoretical contours of external meniscus by the numerical integration the system of differential equations of capillarity. There is calculated the total uncertainty of the external meniscus method.
external meniscus method, surface tension, uncertainty, numerical integration method