| 摘要 |
A multi-stage temperature indicating device having a housing having a bore formed therein having a closed end and an open end, the housing having a first neck region spaced from the closed end, a first internal cavity between the first neck region and the closed end, a second internal cavity between the first neck region and the open end; an indicator rod comprising a first stem stretch and a second stem stretch; an extension segment having a first extension stretch and a second extension stretch, the second extension stretch slidably cooperating with the first stem stretch; the indicator rod and the extension segment slidably positioned in the bore; and a fusible material retaining the indicator rod and the extension segment in the housing, wherein different portions of the fusible material soften at different predetermined temperatures, whereby upon the softening of a first portion of the fusible material allows a spring to urge the indicator rod a first distance out of the housing indicating that a first temperature has been reached and upon the softening of a second portion of the fusible material allows the spring to urge the indicator rod a second distance out of the housing indicating that a second temperature has been reached. |
