US 11,756,400 B2
Self-testing hazard sensing device
Bruce R. Griffith, Geneva, IL (US); Dale Johnson, Elgin, IL (US); Christopher Dearden, Melton Mowbray (GB); Michael Barson, Nuneaton (GB); and Benjamin Wolf, Leicester (GB)
Assigned to Honeywell International Inc., Charlotte, NC (US)
Filed by Honeywell International Inc., Charlotte, NC (US)
Filed on Jan. 14, 2022, as Appl. No. 17/576,253.
Application 17/576,253 is a continuation of application No. 17/018,734, filed on Sep. 11, 2020, granted, now 11,227,473.
Prior Publication US 2022/0139185 A1, May 5, 2022
This patent is subject to a terminal disclaimer.
Int. Cl. G08B 29/14 (2006.01); G08B 17/107 (2006.01); G08B 17/117 (2006.01)
CPC G08B 17/107 (2013.01) [G08B 17/117 (2013.01); G08B 29/145 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A self-testing hazard sensing device, comprising:
a heating element having a material applied thereto for generating aerosol and/or carbon monoxide; and a controller configured to determine whether the self-testing hazard sensing device is functioning properly based on a rate at which a density level of the generated aerosol and/or carbon monoxide decreases.