WarmMark
WarmMark Validated Time Temperature Indicator By Introtech
WarmMark Time-Temperature Indicators monitor your products during storage and shipment, giving you an accurate, non-reversible record of temperature exposure with the passage of time. WarmMark Indicators come in a variety of response temperatures to fit many applications.
If the windows in the WarmMark indicator remain white, there's no problem. If the temperature exceeds the threshold, the indicator window changes to red with time. If the temperature returns to below the threshold, the colour stops changing. In this way, it is possible to estimate how long your product was exposed above the threshold temperature