Device for detecting the presence and disappearance of a target substance and its use in preservative packaging

摘要

The invention relates to a device for detecting the presence and disappearance of a gaseous or liquid target substance with high vapour pressure. The device according to the invention comprises a closed wrapper which is permeable to the target substance and contains a frozen medium in which a coloured indicator and an antagonistic reactant are dissolved. Visual detection is based on the combination of two coupled chemical reactions which involve these two reactants. The device according to the invention is essentially used for preservative packaging.