Irreversible visual indicating device for the first exceeding of a set temperature for products of delicate conservation

摘要

The visual indicating device comprises a body capable of melting at the time of exceeding this temperature and of then making a colorant visible. This body is constituted at least predominantly by a wax of the type with large increase in volume at the time of this exceeding and is enclosed with the colorant in a watertight and opaque casing (3), made so as to burst under the effect of the said increase in volume. The casing (3) is in general constituted by a metal dish (4) which is made watertight by an elastomer membrane (5) with small elongation, and which has a resistance to bursting which is less than that of the dish (4). IMAGE