公开(公告)号：US3755674A

公开(公告)日：1973-08-28

申请号：US3755674D

申请日：1972-03-09

Applicant: COLUMBIA RES CORP

Inventor： MURRAY R ,  GIGNOUX D

IPC: G01N21/894 ,  G01N21/32

CPC classification number: G01N21/894 ,  G01N2201/0813

Abstract: Method of detecting pinhole defects in sheet materials for example tin plate, galvanized steel and thin metallic foils. A modulated ultra-violet light source is directed at right angles onto the advancing sheet material, the edges of the sheet material are shielded from both ambient and ultra-violet light, all non-ultra-violet light is shielded out from beneath the advancing strip, ultra-violet light which has been transmitted through the pinhole defects and said filtering is photomultiplied as a function of pinhole defects in the advancing material. The method is distinguished from prior art in collimating the ultraviolet light source so as to transmit the light at a right angle to the direction of motion of the sheet material and independently baffling the photomultiplier units with respect to each other, so as to define precise lineal zones of detection in said advancing material.

Abstract translation: 检测板材，例如锡板，镀锌钢和薄金属箔的针孔缺陷的方法。 调制的紫外光源以直角定向到前进的片材上，片状材料的边缘与环境和紫外线均被屏蔽，所有非紫外光均从前进条上被屏蔽 已经通过针孔缺陷传播的紫外光和所述过滤作为前进材料中针孔缺陷的函数被光电倍增。 该方法与现有技术的不同之处在于准直紫外线光源，以使光线与片材的运动方向成直角传播，并且独立地使光电倍增管单元相对于彼此阻挡，从而限定 在所述前进材料中精确的检测线。