Sensing Chamber with Enhanced Ambient Atmospheric Flow

• US 20080117065A1
• Filed: 11/20/2006
• Published: 05/22/2008
• Est. Priority Date: 11/20/2006
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Lang, Scott R.
• Granted Patent: US 7,656,302 B2
• Time in Patent Office: Days
• US Class Current: 340/628
• CPC Class Codes: G08B 17/10 Actuation by presence of smoke or gases , e.g. automatic alarm devices for analysing flowing fluid materials by the use of optical means
• CPC Class Codes: G08B 17/107 for detecting light-scattering due to smoke
• CPC Class Codes: G08B 17/113 Constructional details

Abstract

A sensing chamber promotes an inflow of ambient atmosphere by establishing an internal temperature gradiant. A closed loop control system can be provided to maintain the gradiant.

Claims

1. A sensing chamber comprising:

a hollow housing having at least one inflow port and at least one outflow port; and

a non-movable flow inducing element carried in the housing to create a temperature gradient therein.

2. A chamber as claimed in claim 1 wherein the element comprises at least one of a heating element, or a cooling element.

3. A chamber as in claim 1 which includes a temperature indicating feedback element.

4. A chamber as in claim 3 which includes a source of radiant energy and a sensor thereof.

5. A chamber as in claim 4 where the temperature gradient induces flow of ambient atmosphere into the chamber.

6. A chamber as in claim 5 where the housing has first and second internal regions with the flow inducing element carried in one of the regions.

7. A chamber as in claim 6, where at least one flow inducing element is located in a region associated with the inflow port.

8. A chamber as in claim 7 where at least one flow inducing element is located in a region associated with the output port.

9. A chamber as in claim 6 which includes a non-movable heating element and a non-movable cooling element, both carried in the housing.

10. A chamber as in claim 6 which includes temperature regulating circuitry coupled to the flow inducing element and the feedback element.

11. A detector comprising:

an aspirated sensing chamber that includes a flow inducing atmospheric heating element.

12. A detector as in claim 11, the detector having a housing which carries the chamber.

13. A detector as in claim 11 which includes closed loop temperature control circuitry.

14. A detector as in claim 13 where the chamber includes an atmospheric cooling element.

15. A detector as in claim 14 where the sensing chamber includes inflow port and an outflow port.

16. A method comprising:

establishing a region for sensing an airborne ambient condition;

establishing a temperature gradient across at least part of the region to induce an inflow of ambient atmosphere into the region; and

sensing a concentration of the ambient condition in the region.

17. A method as in claim 16 where establishing a temperature gradiant includes heating ambient atmosphere in part of the region.

18. A method as in claim 17 where establishing a temperature gradiant includes cooling ambient atmosphere in part of the region.

19. A method as in claim 16 which includes sensing a temperature parameter and adjusting the gradiant accordingly.