| 摘要 |
<p>An alarm unit includes a housing comprising a back plate and a cover (15,20 fig 1), and a tamper detection system including an operating member 96, extending away from the back plate towards the cover and preferably operating a push switch means 98 via spring 97. The tamper detection system further includes a penetration detection grid 31 that includes at least a portion as a flexible circuit board 80 which may be fixed to a PCB 24. When the cover is closed against the back plate, the flexible board 80 is in contact at one face with the operating member 96 and preferably on the opposite face with boss 96 formed on the cover.</p> |
