Abstract: An emission detection system an enclosed combustion device stack is disclosed. The detection system has a sampling line having a first end exposed to a combusted gas passing through the stack exit port, to receive an undiluted gas sample from the stack exit port. The detection system has an electrostatic particulate matter sensor coupled to a second end of the sampling line, the second end positioned lower than and downstream of the first end, to analyze the undiluted gas sample. The detection system has an exhaust outlet coupled to and downstream of the electrostatic particulate matter sensor, to receive the undiluted gas sample from the electrostatic particulate matter sensor and feed the undiluted gas sample to the primary gas intake line upstream of the enclosed combustion device stack burner.

Abstract: An analog, optical-fiber measuring system compensates for variations in the level of light attenuation occurring in the optical path of the measuring system. The analog, optical-fiber measuring system utilizes a "reference" light transmitted along a common optical-fiber path as the actual "sensing" light. The reference light has a wavelength which differs from the sensing light's wavelength. Effects of the variations in the level of light attenuation are eliminated by monitoring the variations in the attenuation experienced by the reference light along the common optical-fiber path and adjusting the respective intensities of the reference light and the sensing light as a function of the variations. Because the effects of the variations in the level of light attenuation are compensated by an analog scheme, accurate measurement of the selected physical parameter is insured without the need for a microprocessor.

Abstract: A reflecting mirror for reflecting a beam of light emitted from a light source along an optical axis, the mirror comprising at least two spherical sections. Each section is arranged to produce an image of the light source adjacent to but not coincident with the light source.

Abstract: A controlled color light source including a lamp for projecting a beam of light, a power supply for energizing the lamp and a light conduit for sampling a portion of the light emitted from the lamp. A beam splitter is arranged to split the light from the conduit into two channels, and a pair of photo detectors, one for each channel are arranged to receive the light from the conduit via the beam splitter. A divider circuit has a pair of inputs and an output, the inputs being connected to the two photo detectors and an output circuit is connected to the output of the divider circuit for providing an output signal which is proportional to the color of light captured by the conduit.

Abstract: A reflector assembly for projecting a beam of light along an optical axis, the assembly including an enclosure having an aperture for projecting the beam of light and a source of light mounted within the enclosure. A reflecting mirror is disposed within the enclosure and arranged to move axially with respect to the optical axis of the beam of light between positions adjacent the aperture and remote from the aperture. A plurality of reflector segments are disposed between the movable reflector and the aperture in the enclosure, the segments each being defined as a portion of a cone or cylinder and with gaps therebetween arranged so as to permit the passage of air between the segments.