Abstract:
The present invention is directed to a sensor which utilizes an optical fiber interferometer to detect the absorption of a modulated laser beam by a particular chemical species. In particular, one embodiment of the present invention comprises a fiber optic system in which light from a continuously operating laser is modulated prior to passing through a region containing a chemical species of interest. Absorption of the light from the laser causes heating of the chemical species which, in turn, emits thermal energy that is transferred to an optical fiber that is situated in close proximity to the region in which the light is absorbed. In turn, the increase of the temperature of the optical fiber results in a change in the fiber's refractive index, thereby resulting in a change in the transmittance of said interferometer. The change in transmittance of the fiber is converted into an electrical signal in a photodetector. Thereafter, the modulated signal from the photodetector is recovered by phase-sensitive detection, using a lock-in amplifier. In this fashion, the amplitude of the output signal from the amplifier is proportional to the amount of light absorbed by the chemical species of interest. The concentration of this chemical species may thus be determined.
Abstract:
A multichannel optical sensing device is disclosed, for measuring the outr sky luminance or illuminance or the luminance or illuminance distribution in a room, comprising a plurality of light receptors, an optical shutter matrix including a plurality of liquid crystal optical shutter elements operable by electrical control signals between light transmitting and light stopping conditions, fiber optic elements connected between the receptors and the shutter elements, a microprocessor based programmable control unit for selectively supplying control signals to the optical shutter elements in a programmable sequence, a photodetector including an optical integrating spherical chamber having an input port for receiving the light from the shutter matrix and at least one detector element in the spherical chamber for producing output signals corresponding to the light, and output units for utilizing the output signals including a storage unit having a control connection to the microprocessor based programmable control unit for storing the output signals under the sequence control of the programmable control unit.
Abstract:
The system for sensing ions in aqueous solution such as an electroplating bath includes a light source (18) which delivers light including a selected wavelength through a series of optical fibers (20, 24, 26, 32) to probe (14). The probe is partially immersed in the solution (12) and the light is delivered through the solution in the space (94) between prisms (82, 92). The return light is conducted by optical fibers (32,38) to detector or opto-electronic transducer (44). A portion of the original light is diverted by splitter (22) through fiber (42) to opto-electronic transducer (46) so that a comparison of the signals determines the amount of light in selected wavelength which is absorbed in the solution due to ions thereon. The signal processing unit (40) is preferably enclosed in an electromagnetic protected area (16) to avoid the adverse EMI and corrosive atmosphere effects near the electroplating tank (10).
Abstract:
Subsurface contaminants are readily and inexpensively detected and measured by means of a test head positioned at the subsurface site and forming a protected test chamber for the liquids to be tested. The head encloses the end faces of fiber optic elements which carry radiation to the liquid sample from a test instrument located at the surface and which return radiation from the sample to the instrumentation. A connector positioned at the surface decouples the head from the instrumentation, so that the same instrumentation can service a larger number of test sites.
Abstract:
An optical-fiber-based spectrometer utilizes a compact, P-C-board-mountable optical multiplexer which permits multiple channels of reference and measurement data from remote and hostile environments to be analyzed in rapid sequence utilizing synchronized computer data-storage and comparison to give rapid-fire answers to the question of the presence or absence of species of interest in a sample or process being analyzed, the relative light level in the reference and data channels being balanced by an optical attenuator having only an air path, attenuation being effected by controlled misalignment of optical fiber ends.
Abstract:
Concentration of a smoke emanating from a combustion engine is determined by projecting beams of light on the flow of smoke in directions traversing the flow of smoke, detecting intensities of beams of light which have traversed the flow of smoke with a light receiving device and calculating a cross-sectional image of the flow of smoke based on detection signals issued by the light receiving device.
Abstract:
The embodiments herein relate to a system (100) for analyzing a fluid (103). The system (100) comprises a light source (110) configured to emit light for transmission through a first optical transmission means (107a) to a measurement device (105). The measurement device (105) comprises at least a part of the fluid (103) and is configured to be illuminated by the emitted light. The system comprises a second optical transmission means (107b) configured to transmit shadowed or reflected light from the fluid (103) when the measurement device (105) is illuminated to an image capturing device. The image capturing device (113) is configured to capture an image of the fluid (103) in the measurement device (105) based on the transmitted information about the fluid (103). The light source (110) and the one or more image capturing device (113) are remotely arranged from the at least one measurement device (105).
Abstract:
Es sind Vorrichtungen zur Bestimmung der Konzentration zumindest eines Gases in einem Probengasstrom mit einer Analysenkammer (10), in die der Probengasstrom und ein Reaktionsgasstrom einleitbar sind, einem Detektor (48), welcher die durch die Reaktion emittierte optische Strahlung misst und einem Verbindungskanal (22), über den die Analysenkammer (10) mit dem Detektor (48) verbunden ist, bekannt. Zur Steigerung der Effizienz und der Messgenauigkeit dieser Vorrichtungen sowie zur Vermeidung von Ablagerungen an den Wänden der Analysenkammer (10) wird vorgeschlagen, dass der Verbindungskanal (22) als Lichtleiter (26) ausgeführt ist, der sich von der Analysekammer ( 10) bis zum Detektor (48) erstreckt.
Abstract:
Capteur optique d'espèces chimiques comportant : - une source fluorescente de rayonnement infrarouge incohérent (3), comprenant une matrice en verre de chalcogénure dopée par des ions de terre rare couplée ô une source de pompage par une première fibre optique (2); et - au moins un détecteur de rayonnement infrarouge (5) pourvu d'un dispositif de sélection spectrale (50) et agencé pour détecter le rayonnement émis par ladite source fluorescente et ayant traversé une zone de détection (6), ledit détecteur comprenant un élément fluorescent (510) formé par une matrice en verre de chalcogénure dopé par des ions de terre rare, couplée ô une deuxième source de pompage (530) par l'intermédiaire d'une deuxième fibre optique (520). Utilisation d'un tel capteur pour la détection différentielle d'une espèce chimique, et en particulier de CO2.
Abstract:
The present invention is directed to solving the problems associated with the detection of surface defects on metal bars as well as the problems associated with applying metal flat inspection systems to metal bars for non-destructive surface defects detection. A specially designed imaging system, which is comprised of a computing unit, line lights and high data rate line scan cameras, is developed for the aforementioned purpose. The target application is the metal bars (1) that have a circumference/cross-section-area ratio equal to or smaller than 4.25 when the cross section area is unity for the given shape, (2) whose cross-sections are round, oval, or in the shape of a polygon, and (3) are manufactured by mechanically cross-section reduction processes. The said metal can be steel, stainless steel, aluminum, copper, bronze, titanium, nickel, and so forth, and/or their alloys. The said metal bars can be at the temperature when they are being manufactured. A removable cassette includes various mirrors. A protection tube isolates the moving metal bar from the line light assembly and image acquisition camera. assembly and image acquisition camera. A contaminant reduction mechanism applies a vacuum to remove airborne contaminants.