Patent ID: 8632732

Claim:
A device for measuring the water activity of foods, of the type of devices that record water activity with a chemical reaction between water vapor from a food sample, comprising: a cylindrical-shape container, of constant cross section, wherein the container is closed in its bottom end and open in its upper end, and includes a closing to close the upper open end, the container including an inner integral annular groove on which a permeable-material disc is placed, and a marking on an external lower surface of the container that serves to indicate the level up to which should be filled with a homogeneous mixture of food sample under study, for which the water activity level measure is desired, and the permeable-material disc carrying: a reactive substance formed by dissolving a hygroscopic salt into ethylene glycol as a solvent vehicle, and acid-base indicators, consisting of m-cresol purple, bromothymol blue, and thymol blue, by means of which a specific color is defined on the permeable-material disc due to a chemical reaction that occurs between water vapor emanated from the sample under study and the chemical components of said reactive substance.