Duct detector with improved functional test capability

• US 8,939,013 B2
• Filed: 03/16/2012
• Issued: 01/27/2015
• Est. Priority Date: 03/16/2012
• Status: Active Grant

• Current Assignee: Tyco Fire & Security GmbH (Johnson Controls International plc)
• Original Assignee: Tyco Fire & Security GmbH (Johnson Controls International plc)
• Inventors: Brighenti, Donald D., Brooks, Jeffrey R.
• Primary Examiner(s): Macchiarolo, Peter
• Assistant Examiner(s): Megna Fuentes, Anthony W
• Application Number:
  US13/422,368
• Publication Number:
  US 20130239659A1
• Time in Patent Office: 1,047 Days
• Field of Search: 250/574, 356/239.1, 356/432
• US Class Current: 73/28.01
• CPC Class Codes: G01N 21/4738 Diffuse reflection precedence is given to G01N21/55 - G01N21/57 if specular component is taken into consideration, e.g. also for testing fluids, fibrous materials
• CPC Class Codes: G01N 21/53 within a flowing fluid, e.g. smoke
• CPC Class Codes: G08B 17/107 for detecting light-scattering due to smoke
• CPC Class Codes: G08B 17/113 Constructional details
• CPC Class Codes: G08B 29/145 of fire detection circuits

Abstract

A device and method for facilitating convenient functional testing of a duct detector is provided. The device includes a duct detector having a remote-controlled test light mounted in a housing thereof, and a detector chamber defined by a filter screen and a plurality of labyrinth members that allow light emitted by the test light to enter the detector chamber. A functional test of the duct detector can be conducted by activating the test light. If the detector is functioning properly, an amount of light emitted by the test light will be detected by the light detector, thereby simulating the presence of an excessive amount of particulate within the detector chamber. The light detector will then generate an output signal that will cause the actuation of alarms and/or the deactivation of a blower system, thereby indicating functionality of the duct detector.

Claims

1. A method for testing the functionality of a duct detector comprising:

activating a test light located in a main housing of the duct detector using a control device that is remote from the main housing, wherein the main housing is attached to a ventilation duct;

at a light detector located in a detector housing within the main housing, receiving a portion of light emitted from the test light, wherein the received light passes through a plurality of labyrinth members positioned between the test light and the light detector;

determining if the light received at the light detector exceeds a predetermined threshold; and

signaling an alarm when the light received at the light detector exceeds the predetermined threshold.

2. The method of claim 1, wherein determining if the light received at the light detector exceeds a predetermined threshold comprises receiving an output signal from the light detector and comparing the output signal to a predetermined threshold signal level.

3. The method of claim 2, wherein the output signal comprises a current or a voltage.

4. The method of claim 2, further comprising deactivating a blower associated with the duct when the output signal exceeds the predetermined threshold signal level.

5. The method of claim 2, further comprising signaling a clean condition when the output signal exceeds the predetermined signal threshold.

9. The method of claim 1, wherein emitting light from a test light is controlled by a user via wireless control.

10. The method of claim 1, wherein emitting light from a test light is controlled by a user at a fire panel.

6. A method for testing the functionality of a duct detector comprising:

activating a test light located in a main housing of the duct detector;

at a light detector located in the housing, receiving a portion of light emitted from the test light, wherein the received light passes through a plurality of labyrinth members positioned between the test light and the light detector;

receiving an output signal from the light detector and comparing the output signal to a predetermined threshold signal level;

signaling an alarm when the light received at the light detector exceeds the predetermined threshold; and

calibrating the test light to emit a predetermined amount of light, wherein the predetermined amount of light is sufficient to generate an output signal that exceeds the predetermined threshold signal level when a filter screen of the duct detector is in a clean condition.

7. The method of claim 6, wherein the predetermined amount of light is not sufficient to generate an output signal that exceeds the predetermined threshold signal level when the filter screen is in a clogged condition.

8. The method of claim 7, wherein the clean condition of the filter is associated with a proper functioning condition of the duct detector, and wherein the clogged condition of the filter is associated with an improper functioning condition of the duct detector.