Patent ID: 6841380

Claim:
Apparatus for providing an air-ventilated region of constant predetermined water activity value, said apparatus comprising a container and a chamber positioned outside said container, characterized in that: a) said chamber has an opening therein which is closed by a lid; b) said lid has at least one small aperture therein to vent said chamber to the atmosphere; c) said container has an opening therein, to provide access to the interior of said container, and a cover positioned over said opening; d) a rigid tube passes through a wall of said chamber and also through said cover, the outer surface of said tube being an airtight fit with said wall of said chamber and with said cover; whereby (1) said tube connects the inside of said chamber with the inside of said container, and wherein (2) an absorbent material saturated with water or with a saturated salt solution is within said chamber, so that the water activity within said chamber is at said constant predetermined water activity value, and the interior of said container comprises a region which is maintained at said constant predetermined water activity value.