摘要 |
<p>An indicator system with a dispenser providing controlled release of a volatile material contained within a dispenser, which indicates the exhaustion of the volatile material. The dispenser includes a blister that contains a vapor permeable membrane that collapses on a bottom wall due to internal vacuum forces created by the evacuation of volatile material. As the membrane collapses the remaining volatile material migrates to the periphery of the dispenser thereby indicating exhaustion of the volatile material.</p> |