Patent Number: 7,201,036

Title: Residual life indicating system

Abstract: A residual life indicating system for a filter includes a main filter, a sampling filter, and a sensor. Both the main filter and the sampling filter receive an ambient gas meant to be filtered. The sensor connects to the sampling filter and senses the presence of a predetermined chemical in the gas that has been filtered by the sampling filter.

Inventors: Custer; John P. (Stow, OH), Kessler; Kenneth L. (Streetsboro, OH), Harel; Reuben (Solon, OH), Creed; John L. (Girard, OH)

Assignee: Hunter Manufacturing Co.

International Classification: G01N 37/00 (20060101)

Expiration Date: 2019-04-10 0:00:00