As a kind of extremely wetting surface, the surface of superhydrophilic film has become one of the focuses of research in the field of the modern industry and the urban construction because of its self-cleaning, anti-fog and anti-corrosion properties. One method of defining extremely wetting surfaces is the measurement of contact angles, therefore, it is significant to obtain a high precision contact angle in the extremely wetting surface engineering. In this paper, several contact angle algorithms for improving contact angle accuracy for the ultra hydrophilic film surface are proposed, including the high volume method, the circle fitting method and the ellipse fitting method. In addition, it is shown that the accuracy of the calculation can be improved by the circular fitting algorithm when the contact angle is close to zero.

extremely wetting  /  ultra hydrophilic  /  contact angle