| 主权项 |
1. Device for measuring the contact angle of a liquid drop on a material surface, having a lighting device, an image recording device, a shadow surface, at least one data-processing device and at least one drop dispenser, wherein
a. the lighting device configured to generate a light beam parallel to the material surface that reaches the shadow surface, b. the drop dispenser configured to apply a drop of sample liquid to the material surface, and the light beam of the lighting device projects a silhouette of the drop onto the shadow surface, c. the image recording device configured to record an image arising on the shadow surface, characterized in that d. the image recording device is arranged in front of the shadow surface in such a way that its optical axis deviates less than 30° from a perpendicular position with respect to the shadow surface, e. the shadow surface is tilted at an angle less than 90° and greater than 0.5° with respect to the material surface, and f. the data-processing device configured to evaluate the measurement results of the image recording device and to calculate the contact angle from the image of the drop on the shadow surface and the knowledge of the angle of tilt of the shadow surface. |
