摘要 |
A device for a transparent pipe (1) of circular cross-section for optically counting and measuring objects (3) carried with a fluid (2) within the pipe (1), in which the light beams exiting through the wall of the pipe (1) are preferably caught by an optical apparatus (4). The outer radius of the pipe (1) equals or nearly equals the product of the inner radius of the pipe (1) and the proportion of the light refraction index of the fluid within the pipe to the light refraction index of the medium surrounding the pipe. The optical apparatus (4) is located at a camera point (11) at a mean distance from the pipe (1) between a distal point of intersection (10) of light beams (7) hitting the internal wall of the pipe (1) at an angle of about five angular degrees, and a proximal point of intersection (12) of light beams hitting the internal wall of the pipe (1) at an angle of about ninety angular degrees relative to the axis of incidence. |