SENSORS AND METHODS FOR DETERMINING WHETHER AN ITEM HAS BEEN EXPOSED TO AN ENVIRONMENTAL CONDITION

摘要

A method for determining whether an item has been exposed to an environmental condition during a monitoring period. The method includes placing a sensor at least in proximity to the item at the beginning of the monitoring period so that the sensor will be exposed to a level of an environmental condition that can be correlated to an exposure level of the item to the environmental condition; reading the sensor; and determining from reading the sensor whether the item has been exposed to the environmental condition. The sensor includes a detecting material comprising a photochromic or photothermochromic material, the detecting material selected so that upon exposure to the environmental condition the detecting material exhibits a detectable color change.