AIR TREATING DEVICE

摘要

AIR TREATING DEVICE Peter W. Hamilton William P. Lewis An air treating device in which the exhaustion of the operative fluid is visually signaled by a run-out signal system. The operative fluid and an immiscible signal fluid are held in a reservoir having associated therewith a substrate that selectively first wicks the operative fluid onto the evaporative surface portion of said substrate and, when the operative fluid is substantially depleted the substrate then transports the signal fluid to the evaporative surface. The signal fluid is of a different hue from the operative fluid to provide an easily observed signal denoting exhaustion of the operative fluid.