| 摘要 |
A pinhole detecting apparatus includes a first electrode which may be a needle electrode or a brush electrode. The first electrode is positioned to be closed to or brought into contact with a member to be detected such as an insulation sheet which seals food, a closed container which contains medicine, or the like. Such a member to be detected is put on a second electrode which may be a conveyer made of electrically conductive material. When a high voltage is applied between the first and second electrodes, if a pinhole was formed on the member to be detected, a discharge current flows between the first and second electrodes through the pinhole, whereby the pinhole can be detected through detection of such a discharge current. A portion of the member to be detected below the first electrode is cooled by an air stream or other coolant when the high voltage is applied to the first and second electrodes, whereby the portion of the member to be detected is prevented from being thermally destroyed. Therefore, it becomes possible to increase the voltage being applied to the first and second electrodes. |
