Abstract: An apparatus for validating the operation of an optical scanning system is provided. The apparatus includes one or more scanning illumination beams (6) for scanning an object, and one or more observing beams that comprise light scattered by the object being scanned, which inversely follow the path of the illumination beams. The apparatus further includes a reflector structure (9) arranged to reflect both the illuminating beams and observing beams scattered by a reference target (10) for a portion of each scan (e.g., a scan may be a 360-degree scan in the case of a circular scanning system). The apparatus still further includes the reference target (10) arranged to be scanned by the illumination beams reflected by the reflector structure during said portion of each scan. Light scattered by the reference target is received as the observing beams, and their optical properties are continuously monitored to validate the proper operation of the optical scanning system.

Abstract: An apparatus for validating the operation of an optical scanning system is provided. The apparatus includes one or more scanning illumination beams (6) for scanning an object, and one or more observing beams that comprise light scattered by the object being scanned, which inversely follow the path of the illumination beams. The apparatus further includes a reflector structure (9) arranged to reflect both the illuminating beams and the observing beams for a portion of each scan (e.g., a scan may be a 360-degree scan in the case of a circular scanning system). The apparatus still further includes a reference target (10) arranged to be scanned by the illumination beams reflected by the reflector structure during said portion of each scan. Light scattered by the reference target is received as the observing beams, and their optical properties are continuously monitored to validate the proper operation of the optical scanning system.

Abstract: The present invention relates to a backscattering apparatus and method for optical scanning along a circular path using one or more optical illuminators and receivers. More particularly, it relates to an apparatus and method of focusing one or more beams of light into one or more beam spots, scanning the common beam spot(s) across a circular path and receiving light backscattered from the beam spot(s) with one or more detectors. A rotationally mounted scanning optics having an optical axis parallel to but not coaxial with the axis of rotation is used to accomplish these functions. A motor may be operatively linked to the scanning optics to cause the same to rotate at a constant angular velocity whereby, with appropriate signal generating detector and signal processing electronics, the number and size of particles suspended in a fluid medium exposed to the beam spot(s) can be determined.

Abstract: An in-situ imaging system suitable for analyzing particles or droplets contained in process reactor vessels or pipelines at full process concentrations is disclosed. The system includes a light source capable of high peak power output operated in a pulsed mode that is located inside of a probe. The light from the light source is coupled into an optical fiber. The light is carried by the optical fiber to a lens system near the end of the probe which focuses the light through a window to the area which coincides with the field of view in the focal plane of the imaging optics. The imaging optics collect the light which is back-scattered from particles or droplets, magnifying the image and projecting it onto an image detector such as a CCD array.

Abstract: The present invention describes an optical technique for analyzing undiluted, multi-phase fluid flows as typically encountered inside reactor vessels or flow lines in the chemical industries. In particular the technique uses a pulsed, coherent light source and measures the back-scattered light collected over a wide scattering angle. A light beam is relayed via a set of lenses down a long probe tube, through a window at a probe tip to illuminate the material that is passing past the window. The light beam is pulsed to "freeze" the motion of the particles streaming past the window. The backscattered light is collected by the same set of optics and is focused on the front surface of a CCD chip.

Abstract: Apparatus and a method are disclosed for determining the sizes of particles entrained in a fluid over a relatively wide range of sizes and determining the distribution of particles in a plurality of size increments. A sample of particles is fed into a drop tube, allowing the particles to be distributed at a relatively low density and fall through a sensing region defined at an intermediate point in the drop tube. A laser diode produces coherent light that is focused with a lens, forming a sheet of coherent light that is directed transversely through transparent sides of the drop tube toward a lens that focuses the sheet of coherent light on a photodetector. A laser intensity control circuit maintains a constant light intensity output from the laser diode when no particle is present in the sensing region and compensates for ambient light. When a particle in the size range of 32.mu. to 4000.mu.