| 摘要 |
<p>A device for indicating irreversibly, by means of color change, that temperatures equal to or above 7.degree.C, 10.degree.C or 13.degree.C have occurred. A container is filled with a liquid which freezes at the temperature to be monitored and which expands on thawing. A dye is dissolved in the liquid. Alternatively, the dye is placed in powder form on an indicating paper. The capsule is placed in proximity to the indicating paper. The container is activated by freezing. Any increase in temperature after activation causes the liquid to melt and expand. The container breaks open for example, along a seam, allowing the liquid to escape contacting the indicating paper, thereby dying the paper and producing an irreversible signal.</p> |
