US 12,072,293 B2
Probing film that absorbs and reacts with gases, with light of different wavelengths for higher gas sensitivity
Peter Tobias, Minneapolis, MN (US); and Christopher Zins, Coon Rapids, MN (US)
Assigned to HONEYWELL INTERNATIONAL INC., Charlotte, NC (US)
Appl. No. 16/074,847
Filed by Honeywell International Inc., Morris Plains, NJ (US)
PCT Filed Feb. 10, 2017, PCT No. PCT/US2017/017288
§ 371(c)(1), (2) Date Aug. 2, 2018,
PCT Pub. No. WO2017/139523, PCT Pub. Date Aug. 17, 2017.
Claims priority of provisional application 62/294,192, filed on Feb. 11, 2016.
Prior Publication US 2020/0124539 A1, Apr. 23, 2020
This patent is subject to a terminal disclaimer.
Int. Cl. G01N 21/78 (2006.01)
CPC G01N 21/783 (2013.01) [G01N 2201/0484 (2013.01); G01N 2201/0621 (2013.01); G01N 2201/0627 (2013.01)] 8 Claims
OG exemplary drawing
 
1. A system for distinguishing a nuisance gas from a target gas or group of target gases, the system comprising:
a paper tape;
a light source configured to emit at least three wavelengths of light selected from red, green, blue, or ultra-violet wavelength;
a detector configured to detect a reflected portion for each of the three wavelengths of light which reflects from the paper tape; and
a processor/controller connected to the detector, the processor/controller configured to:
generate a reference level to which subsequent data is compared by individually flashing the light source on a fresh paper tape before exposing the paper tape to a gas stream;
receive a digital signal containing detection information for the reflected portion from the detector;
calculate, for each light pulse of each wavelength of the at least three wavelengths of light emitted from the light source, an adjusted count based on an original intensity of the light emitted from the light source and an actual intensity of the reflected portion of the light; and
perform, based on the adjusted count for each light pulse of each wavelength of the at least three wavelengths of light, pattern recognition to determine at least one of a characteristic or a color pattern of the reflected portion for each of the at least three wavelengths of light to distinguish the nuisance gas from the target gas or the group of target gases, wherein a presence of the target gas or the group of target gas warrants an alarm, wherein a presence of the nuisance gas does not warrant the alarm, wherein the nuisance gas is not the target gas or a member of the group of target gases but is detectable by the paper tape, wherein distinguishing the nuisance gas from the target gas or the group of target gases reduces false alarms, and wherein performing pattern recognition includes at least one of:
comparing a first ratio of adjusted counts for red wavelength to adjusted counts for green wavelength and a second ratio of adjusted counts for blue wavelength to the adjusted counts for green wavelength,
comparing the first ratio of the adjusted counts for red wavelength to the adjusted counts for green wavelength and a third ratio of adjusted counts for ultra-violet wavelength to the adjusted counts for green wavelength, or
comparing the second ratio of the adjusted counts for blue wavelength to the adjusted counts for green wavelength and the third ratio of the adjusted counts for ultra-violet wavelength to the adjusted counts for green wavelength.