| 主权项 |
1. A method of measuring the inside diameter of a hollow body of revolution (2) that is transparent or translucent and that is defined by an inside face (4) and an outside face (5), the body presenting an axis of revolution along a vertical axis (z), the method consisting in illuminating the hollow body (2) by means of a diffuse light source (9) and in recovering the light rays emerging from the hollow body (2) in order to form at least one image, and being characterized by:
illuminating the hollow body (2) on one side by means of a diffuse light source (9) so that the incident light rays (Ii) pass through the hollow body (2) along at least one cross-section perpendicular to the axis of revolution and in which the inside diameter is to be measured along a measurement axis (x), the light source (9) presenting two light boundaries (91, 92) spaced apart along the measurement axis (x) so as to create two light transitions (T1, T2) in the image that are spaced apart from each other and diametrically opposite about the vertical axis (z), corresponding to emerging light rays that propagate along respective lines tangential to the inside face (4) and perpendicular to the diameter; from the side of the hollow body that is opposite from its illuminated side, and by acting along an optical axis (y) that is perpendicular to the vertical axis (z) and perpendicular to the measurement axis (x), recovering the light rays that are reflected and refracted by the hollow body (2) so as to form at least one image (J) in which there appear at least the two light transitions (T1, T2); and processing the image (J) so as to determine the distance along the measurement axis (x) between the two light transitions (T1, T2) in order to determine a measurement for the inside diameter of the hollow body. |
