Protective cover for chamberless point sensor

Abstract

A covered chamberless particulate detector includes a chamberless detector configured to produce a signal when particulate sensing events occurs, one or more optical emitters configured to emit one or more emitting cones of light, one or more optical sensors defining one or more receiving cones and configured to detect occurrence of particulate sensing events, and a protective cover defining an inside region and an outside region. Each of the one or more emitting cones of light is configured to overlap with each of the one or more receiving cones, thereby creating one or more sensing volumes which may be in the inside region, the outside region, or both regions. The protective cover can be transparent, partially transparent, or opaque, and can include apertures. The optical emitters and detectors can use one or more wavelengths, allowing discrimination of various airborne particulates.

1 . A covered chamberless particulate detector comprising:
 a chamberless detector configured to produce a signal when particulate sensing events occurs;   one or more optical emitters disposed on the chamberless detector, configured to emit one or more emitting cones of light;   one or more optical sensors disposed on the chamberless detector, defining one or more receiving cones; and   a protective cover defining an inside region and an outside region, the protective cover disposed on the chamberless detector;   wherein each of the one or more optical sensors is configured to detect occurrence of the particulate sensing events.   
     
     
         2 . The covered chamberless particulate detector of  claim 1 , wherein each of the one or more emitting cones of light is configured to overlap with each of the one or more receiving cones, thereby creating one or more sensing volumes. 
     
     
         3 . The covered chamberless particulate detector of  claim 2 , further configured to create one or more of the sensing volumes in the inside region. 
     
     
         4 . The covered chamberless particulate detector of  claim 2 , further configured to create one or more of the sensing volumes in the outside region. 
     
     
         5 . The covered chamberless particulate detector of  claim 1 , wherein the one or more optical emitters comprises two optical emitters, each configured to emit a different wavelength of light. 
     
     
         6 . The covered chamberless particulate detector of  claim 1 , wherein the one or more optical sensors comprises two optical sensors, each configured to detect a different wavelength of light. 
     
     
         7 . The covered chamberless particulate detector of  claim 1 , wherein the protective cover comprises a material that has a transparency of at least 40%. 
     
     
         8 . The covered chamberless particulate detector of  claim 1 , wherein the protective cover has a plurality of apertures therethrough, the apertures configured to:
 permit light from each of the one or more emitting cones of light to illuminate the outside region;   permit light from the outside region to enter the inside region; and   permit fluid communication between the outside region and the inside region.   
     
     
         9 . The covered chamberless particulate detector of  claim 8 , wherein the plurality of apertures are configured in a geometrical pattern selected from the group consisting of: parallel latitudes and meridian longitudes. 
     
     
         10 . The covered chamberless particulate detector of  claim 1 , wherein a ratio of a surface area of the apertures to a total surface area of the protective cover is at least 40%. 
     
     
         11 . The covered chamberless particulate detector of  claim 1 , wherein the protective cover comprises a material that is selected from the group consisting of: glass, plastic, polymer, fiberglass, resin, and metal. 
     
     
         12 . The covered chamberless particulate detector of  claim 1 , wherein an inside surface of the protective cover has a reflectivity that is less than 4%. 
     
     
         13 . The covered chamberless particulate detector of  claim 1 , further comprising a protective cover rim, the protective cover rim disposed on the protective cover in a region where the protective cover matingly attaches to the chamberless detector. 
     
     
         14 . The covered chamberless particulate detector of  claim 12 , further comprising a plurality of protective cover rim apertures disposed on the protective cover rim, the protective cover rim apertures configured to receive a connector for attaching the protective cover to the chamberless detector. 
     
     
         15 . A method of using a covered chamberless particulate detector that comprises one or more optical emitters, one or more optical sensors, and a protective cover over the optical emitters and the optical sensors that defines an inside region and an outside region, the method comprising:
 emitting one or more emitting cones of light from the one or more optical emitters;   receiving light in one or more receiving cones by the one or more optical sensors; and   detecting particulate sensing events, and producing a signal denoting occurrence of the particular sensing events, based on presence of particulate material in one or more sensing volumes defined by an overlap of the one or more emitting cones of light and the one or more receiving cones;   wherein the one or more sensing volumes are located in the inside region, the outside region, or both the inside region and the outside region.   
     
     
         16 . The method of  claim 15 , wherein the one or more sensing volumes are created in the inside region. 
     
     
         17 . The method of  claim 15 , wherein the one or more sensing volumes are created in the outside region. 
     
     
         18 . The method of  claim 15 , wherein the protective cover has a plurality of apertures therethrough, the apertures configured to:
 permit light from each of the one or more emitting cones of light to illuminate the outside region;   permit light from the outside region to enter the inside region; and   permit fluid communication between the outside region and the inside region.   
     
     
         19 . The method of  claim 15 , wherein a ratio of a surface area of the apertures to a total surface area of the protective cover is at least 97%. 
     
     
         20 . The method of  claim 15 , wherein the protective cover comprises a material that has a transparency of at least 90%.