The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 23, 2002
Filed:
Mar. 26, 1999
Pierre Bernard, St-Augustin-de-Desmaures, CA;
Serge Caron, Quebec, CA;
Marco St-Pierre, Val-Bélair, CA;
Jaime Lara, Montreal, CA;
Other;
Abstract
An end-of-service indicator for use with a respirator cartridge, the end-of-service indicator having an optical waveguide having two extremities, one of the extremities being connected to a light source, the other of the extremities being connected to a detector which measures the intensity of light guided and transmitted by the fiber. An alarm is connected to the detector and is triggered when the intensity of light measured by the detector is below a predetermined level. An important aspect of the end-of-service indicator is that at least a portion of the optical fiber is porous. In use, the end-of-service indicator is placed inside a respirator cartridge having a gas/vapor sorbent, so that when the respirator cartridge is used in a toxic environment, the gas/vapor sorbent and the porous glass gradually become saturated. This porous glass will absorb the gas/vapor in the same fashion as the sorbent used in the respirator cartridge, thereby lowering the guiding and transmission properties of the optical fiber which loses the necessary conditions to guide light.