How to overcome the uncertainties of polynomial fitting in contact angle determination?

Abstract

In the present work an easily implementable method is introduced for contact angle determination using sessile drops with a missing apex. Instead of fitting the drop-profile itself, the polynomial fitting is applied to the difference between the drop profile and the circumcircle, independently for both sides of the drop. The derivative value of this difference at the contact point is used to correct the slope obtained analytically from the circumcircle.