Method and apparatus for the determination of the contact angle from the drops of curvature radius by means of optical distance measurement

摘要

It is a method for the determination of the contact angle (φ) between a sample surface (3), a gaseous environment and a on the surface of the specimen (3) arranged drop (5), wherein the droplets (5) a curved surface (7), an axis of symmetry (a_Sy-A_Sy) and a defined volume (v_T) has. In the method, an object on the basis of reflective property of the surface (7) of the drop (5) on the droplet surface shown, whereby the position of the object to the optical axis (a - a) of an optical measuring system and the position of the object to the surface of the specimen (3) is known, and wherein the axis of symmetry (a_Sy-A_Sy) of the drop (5) in or near the optical axis (a - a) is arranged. The distance between the image and the optical axis (a - a) of the drop (5) is measured. The radius of curvature of the drop (5), by means of the measured distance and the contact angle is determined by means of the radius of curvature.