| abstract |
The disclosure concerns an indicator for providing a time/temperature integrated indication of the temperature history of a deep-frozen product through the diffusion of water along a cellulose wick. The cellulose wick is provided on itself with a water soluble, hydrate forming substance, such as sodium chloride and citric acid. The wick is covered in a plastic covering with an opening in the covering exposing the wick to water at the product, and the advance of the water front along the wick is indicated by a time/temperature indicator adjacent the wick and/or by an acid/base indicator on the wick and spaced from the indicator. |