| 摘要 |
<p>Tamper proof apparatus for verification that a critical temperature has been reached or exceeded includes a permanently sealed casing and cap containing a thermal element connected to a rotatable cam having a temperature indicator extending outwardly therefrom adapted to rest under a transparent window in the cap when critical temperature has been reached. Maximum and minimum temperature stops on the cap prevent movement of the indicator beyond preselected positions. An opening through the cap engages a removablel shipping pin cooperating with either the maximum or minimum temperature stop to prevent movement of the indicator during shipment or storage. A locking spring connected to the cap traverses the lateral surface of the cam until the spring engages a shoulder formed in the cam. The shoulder and spring have, respectively, a first spur and a second spur that engage in permanently locked position when a critical temperature has been reached. As described heretofore, the cam, spring, and maximum and minimum temperature stops can be arranged, prior to sealing the cap and casing, to indicate that either a maximum or a minimum temperature has been reached. Another embodiment has two separate spring mounting positions, and two separate cam shoulders, which alternatively can be arranged, prior to sealing, to verify that either a maximum or a minimum has been reached.</p> |
