An improved recording device is described, useful for measuring the integrated time-temperature or integrated radiation-dosage history of an article, comprising a substrate onto which an acetylenic compound, containing at least two conjugated C.tbd.C groups, in an inactive form, is deposited. The inactive form is capable of being converted by melt or solvent recrystallization to an active form, which undergoes 1,4-addition polymerization resulting in an irreversible, progressive color change. The color change produced at any given point in time represents an integrated time-temperature history of thermal annealing or integrated radiation-dosage history of exposure to actinic radiation to which an article has been exposed.
Also described is a process for producing an inactive form of the acetylenic compound. A film and a fiber, made from the inactive form of an acetylenic compound are also described.