| 摘要 |
<p>An optical measuring device comprising a gauging head (1) provided with a measuring gate (2) forming a guideway (G) for an article (3) whose dimensional properties are to be measured. A parallel beam of light (P) is established between the opposing walls of guide members (M) of the measuring gate (2), which are provided with slits (S) for emission and reception of the parallel beam. To remove or prevent the collection of particulate contaminant on the optical components (4, 5, 6, 7) within the gauging head (1) the guide members (M) have internal ducts (D) so that air may be directed to the ducts (D) and passed through each opposing slit (S) to set up a curtain of air across the measuring gate (2) thus repelling particulate contaminant floating in the guideway which would otherwise enter the slits (S).</p> |
