| 摘要 |
A thaw indicator unit for sensing and permanently recording a thawing event experienced by a temperature sensitive food or other item, the unit having a container of transparent, non-toxic material, and having a hermetically sealed chamber containing a frozen color change medium having at least two segments of differently colored frozen aqueous compositions, the segments being juxtaposed along an interface of molecular thickness, and at least one of the segments being substantially homogeneously colored differently from at least one juxtaposed other colored segment, wherein the colorants are food grade materials, and whereby the unit when placed on, in or in close proximity to the item will record any first thawing event by way of thawing of the juxtaposed segments and intermixing thereof at least at the interface thereof to produce at least a visible section of an intermix of said compositions and having a markedly different and readily visible color from that of the juxtaposed segments.
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