MALFEASANT MOUTH OPENING DETECTING METHOD AND DEVICE FOR VESSEL

摘要

PURPOSE: To monitor without reliance on radioactive substances by connecting a region of an oscillation circuit without power source to the inner face of the cap and another region to the main body, and by breaking the circuit when opened. CONSTITUTION: An oscillation circuit assembly 29 is intervened between a closure 25 and a body 23. The assembly 29 contains an insulating film 31 printed with one-turn spiral 33 thereon. The overlapped ends 35 and 37 of the spiral are mutually insulated to form a capacitance parallel to an inductance functioning as an oscillation circuit or a parallel tuning circuit. The opening rim 39 of the body 23 is sealed with the film 31 after the container is filled with the contents. A part of the spiral and the portion of the film adjacent to this part are pasted with a spot 41 of adhesive that has not yet been hardened. When the closure 25 is screwed to the body, the tuning circuit is broken by removing the closure because the adhesive spot 41 sticks to the inner face of the closure 25 causing the spiral 33 adhered thereto.