| 摘要 |
A multi-stage temperature indicating device having a housing with a bore, closed and open ends, the housing having a first neck region, 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; an extension segment with first and second extension stretches that slidably cooperate; the indicator rod and the extension segment; 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; when a first portion of the fusible material softens, a spring urges the indicator rod a first distance out of the housing at a first temperature, when a second portion of the fusible material softens, the spring urges the indicator rod a second distance out of the housing at a second temperature. |
