CENTER MARK SENSOR APPARATUS

摘要

PURPOSE:To provide a center mark sensor capable of preventing the intrusion of an obstacle in a visual field of a photographing means and keeping clean a center mark target. CONSTITUTION:A photographing means (2) is loaded on a moving apparatus used in a coke oven and photographs a center mark target (12) located near a rail in the coke oven and the mark (14) attached on the center mark target (12) is distinguished. When the moving apparatus starts to move, air blowing means (20 and 28) quickly encloses a visual field of the photographing means (2) predetermined so as to cover the center mark target (12) by air curtain and an air blowing means (30) keeps the simply enclosed visual field at positive pressure with its air blow.