Abstract: A method of inspecting a lateral pipe extending from a manhole, said method comprising: (a) inserting an imaging head into said manhole using a positioning system, said imaging head connected to an elongated member and comprising an imaging device adapted to convert an image to an image signal, a lens optically coupled to said imaging device, and at least one lamp suitable for projecting a light beam, said lamp having a beam that is adjustable to enable said beam to move relative said imaging device; (b) imaging a target located within said lateral pipe; (c) holding said imaging device essentially steady while imaging said target and adjusting said beam to adjust the illumination of said target.

Abstract: An imaging system comprising a parabolic reflector having a base and defining a first axis, a light source disposed proximate the base essentially along the first axis, an imaging device comprising a zooming lens having a second axis, the imaging device being disposed in front of the light source along the first axis such that the second axis and the first axis are essentially coincident.

Abstract: An imaging system comprising a parabolic reflector having a base and defining a first axis, a light source disposed proximate the base essentially along the first axis, an imaging device comprising a zooming lens having a second axis, the imaging device being disposed in front of the light source along the first axis such that the second axis and the first axis are essentially coincident.

Abstract: The present invention relates to methods and apparatus utilizing distributed temperature sensing (DTS) to monitor the temperature of a cured-in-place pipe liner to determine if proper curing temperatures and times are achieved. More particularly, an optical fiber is placed between the pipe and the liner running the entire length of the liner. The optical fiber is coupled to a DTS unit. During curing of the liner, the DTS unit sends light pulses down the fiber from one end and detects the characteristics and time delay of light backscattered to the unit. The characteristics are indicative of the temperature of the optical fiber, while the delay is indicative of the round trip time of the light within the fiber, and thus the distance from the DTS unit from which any particular backscatter signal originated.

Abstract: A method and apparatus utilizing distributed temperature sensing (DTS) to monitor the temperature of a cured-in-place pipe liner to determine if proper curing temperatures and times are achieved. More particularly, an optical fiber is placed in the pipe between the original pipe and the liner running the entire length of the liner. The optical fiber is coupled to a DTS unit at one end. During curing, the DTS unit sends light pulses down the fiber and detects the characteristics and time delay of light backscattered to the unit. The characteristics of the backscattered light is indicative of the temperature of the fiber while the round trip time delay is indicative of the distance down the fiber from the DTS unit from which that particular backscatter signal originated.

Abstract: A method of inspecting a lateral pipe extending from a manhole, said method comprising: (a) inserting an imaging head into said manhole using a positioning system, said imaging head connected to an elongated member and comprising an imaging device adapted to convert an image to an image signal, a lens optically coupled to said imaging device, and at least one lamp suitable for projecting a light beam, said lamp having a beam that is adjustable to enable said beam to move relative said imaging device; (b) imaging a target located within said lateral pipe; (c) holding said imaging device essentially steady while imaging said target and adjusting said beam to adjust the illumination of said target.

Abstract: An imaging system comprising a parabolic reflector having a base and defining a first axis, a light source disposed proximate the base essentially along the first axis, an imaging device comprising a zooming lens having a second axis, the imaging device being disposed in front of the light source along the first axis such that the second axis and the first axis are essentially coincident.

Abstract: A method of inspecting a lateral pipe extending from a manhole, said method comprising: (a) inserting an imaging head into said manhole using a positioning system, said imaging head connected to an elongated member and comprising an imaging device adapted to convert an image to an image signal, a lens optically coupled to said imaging device, and at least one lamp suitable for projecting a light beam, said lamp having a beam that is adjustable to enable said beam to move relative said imaging device; (b) imaging a target located within said lateral pipe; (c) holding said imaging device essentially steady while imaging said target and adjusting said beam to adjust the illumination of said target.

Abstract: The present invention relates to method and apparatus utilizing distributed temperature sensing (DTS) to monitor the temperature of a cured-in-place pipe liner to determine if proper curing temperatures and times are achieved. More particularly, an optical fiber is placed in the pipe between the original pipe and the liner running the entire length of the liner. The optical fiber is coupled to a DTS unit at neo end. During curing of the liner, the DTS unit sends light pulses down the fiber from one end and detects the characteristics and time delay of light backscattered to the unit. The characteristics of the backscattered light is indicative of the temperature of the optical fiber, while the time delay between the sending of the light pulse and the detection of any portion of the backscatter signal is indicative of the round trip time of the light within the fiber, and thus the distance down the fiber from the DTS unit from which that particular backscatter signal originated.

Abstract: A method of inspecting a lateral pipe extending from a manhole, said method comprising: (a) inserting an imaging head into said manhole using a positioning system, said imaging head connected to an elongated member and comprising an imaging device adapted to convert an image to an image signal, a lens optically coupled to said imaging device, and at least one lamp suitable for projecting a light beam, said lamp having a beam that is adjustable to enable said beam to move relative said imaging device; (b) imaging a target located within said lateral pipe; (c) holding said imaging device essentially steady while imaging said target and adjusting said beam to adjust the illumination of said target.

Abstract: A method of inspecting a lateral pipe extending from a manhole, the method comprising: (a) extending an imaging head into the manhole using a positioning system, the imaging head comprising an imaging device and at least one lamp capable of producing a light beam, the positioning system comprising an elongated member and a targeting fixture operatively connected thereto, the imaging head being attached to one end of the elongated member, the targeting fixture having a distal end biased outwardly from the imaging head; (b) placing the distal end on a rigid surface proximate to the lateral pipe; (c) pushing down on the elongated member such that the distal end resiliently moves toward the imaging head, thereby allowing the light beam to be centered approximately in the lateral pipe; and (d) imaging a target located within the lateral pipe.

Abstract: A method of inspecting a lateral pipe extending from a manhole, the method comprising: (a) extending an imaging head into the manhole using a positioning system, the imaging head comprising an imaging device and at least one lamp capable of producing a light beam, the positioning system comprising an elongated member and a targeting fixture operatively connected thereto, the imaging head being attached to one end of the elongated member, the targeting fixture having a distal end biased outwardly from the imaging head; (b) placing the distal end on a rigid surface proximate to the lateral pipe; (c) pushing down on the elongated member such that the distal end resiliently moves toward the imaging head, thereby allowing the light beam to be centered approximately in the lateral pipe; and (d) imaging a target located within the lateral pipe.

Abstract: A two-terminal bidirectional semiconductor switching device comprising a body of silicon semiconductor material having in one portion a five-zone switching element and, in another portion integral therewith, a three-zone bidirectional voltage-sensitive breakdown element, there being means including another portion of the body connecting the three-zone element as a gating element to said five-zone element so as to trigger conduction therein bidirectionally when voltage breakdown occurs in either direction in the three-zone element.

Abstract: In planar silicon semiconductor devices of the PN junction type, field plates overlie the silicon dioxide-silicon nitride film on the device surface to inhibit inversion formation of conductive channels on the device surface. The field plates are connected to a more heavily doped zone on one side of a PN junction and extend some distance over the lightly doped zone on the other side of the PN junction.At high reverse biases, the presence of trapping centers produces a charge level at the device surface, resulting in current channeling which produces excessive reverse leakage current. This effect is avoided or reduced by omitting the silicon nitride layer in a portion overlying the more lightly doped zone and spaced away from the PN junction boundary. This omission eliminates a portion of the oxide-nitride interface which appears to be the locus of such trapping centers.