Abstract: The optical sensor contains an optical waveguide (1) with a substrate (104), waveguiding material (105), a cover medium (106) and a waveguide grating structure (101-103). By means of a light source (2), light can be emitted to the waveguide grating structure (101-103) from the substrate side and/or from the cover medium side (101-103). With means of detection (11), at least two differing light proportions (7-10) radiated from the waveguide (1) can be detected. For carrying out a measurement, the waveguide can be immovably fixed relative to the light source (2) and the means of detection (11). The waveguide grating structure (101-103) itself consists of one or several waveguide grating structure units (101-103), which if so required can be equipped with (bio-)chemo-sensitive layers. The sensor permits the generation of absolute measuring signals.

Abstract: A sampling material for a carbonyl compound in a gas comprising a reagent capable of converting a carbonyl compound to a derivative thereof supported on a cation exchanger; and a sampling cartridge for a carbonyl compound in a gas wherein a sampling material for a carbonyl compound in a gas comprising a reagent capable of converting a carbonyl compound to a derivative thereof supported on a cation exchanger is packed in a column are provided. The sampling cartridge can be used for analyzing a carbonyl compound such as formaldehyde with ease and at a high sensitivity and high accuracy, and has excellent storage stability.

Abstract: The present invention provides an apparatus and method for determining the concentration of CO gas in a fuel reformate stream such as in a PEM fuel cell vehicle. This invention protects the fuel cell catalyst by controlling the reformate stream system to minimize the CO and reduce it by a novel catalyst system that selectively converts CO to methane but does not react with carbon dioxide and hydrogen. The catalyst may reduce the CO to methane by reaction with hydrogen. The preferred embodiment both monitors the CO by a thermal differential sensing means and an optical biomimetic sensor and or a conductivity sensor. These sensors respond to the CO gas and are monitored by one or more monitoring sensors such as the temperature and or conductivity difference between the control and the catalytic material such as nickel and in the biomimetic sensor an optical change is monitored.

Abstract: The present invention pertains to biosensors based on uniquely designed polymer optical waveguides that are adaptable to a variety of environments, and to both chemical and biological species. In particular, the invention relates to polymer-based, index of refraction-mediated analyte sensing devices.

Abstract: Methods and devices for rapidly analyzing groups of reactions are disclosed. The method includes the steps of contacting a fluid sample from one of the reaction mixtures with a sorbent, trapping at least one component of the fluid sample on the sorbent, and detecting the at least one component of the fluid sample trapped on the sorbent. The contacting step, the trapping step, and the detecting step are carried out at least once for each of the reaction mixtures in rapid serial or parallel fashion. The present invention is useful for screening combinatorial libraries, especially libraries of catalysts made through parallel synthesis, but the disclosed methods and devices can be used to analyze a broad spectrum of chemical transformations.

Abstract: Described herein is a NOx adsorber that reduces the amount of NOx in the exhaust stream of a lean-burn internal combustion engine. The adsorber incorporates a small amount of lithium along with a catalyst, an alkali material, and a support material. The lithium acts to facilitate the reduction of absorbed NOx, thereby lowering NOx concentrations in the exhaust gas.

Abstract: A fluorescence-based method for highly sensitive and selective detection of molecules of basic gases, such as dimethyl methylphosphonate (DMMP), Sarin, Soman and other chemical warfare agents, is proposed. The method employs the effect of strong fluorescence change in a solvatochromic dye isolated in a matrix of the hydrogen bond acidic polymer. In one preferred embodiment the dye and polymer matrix are chosen such that the hydrogen-bond interaction between them results in depression of the fluorescence yield of the sensitive material prior its interaction with the molecules of basic gases. The interaction between the molecule of basic gases and the acidic polymer matrix breaks the hydrogen bond of the dye with the polymer matrix “releasing” the dye and returning it back into the state with a low solute-solvent interaction. That results in strong enhancement of the dye florescence quantum yield and shift of the dye fluorescent spectrum in the direction of shorter wavelengths.

Abstract: A biomimetic reagent system is provided containing an oxygen donor and a catalyst based on porphyrin, which are applied to a carrier. A device that contains the system is also provided for determining components of gas or vapor samples, especially aromatics, such as benzene. A process for hydroxylating aromatics, such as benzene, using the biomimetic reagent system is also provided.

Abstract: A method is described for determining the presence of a volatile component in a test sample. The method involves use of two separate vessels, one of which is capable of being placed wholly within the other vessel. The test sample is placed in the larger vessel, and an indicator solution is placed in the smaller, inner vessel. Then a gas-tight closure is placed on the top of the outer, larger vessel. The assembly is heated to an elevated temperature, whereby the volatile target analyte which is released from the test sample transfers to the inner vessel and is absorbed by the indicator solution. The indicator solution can be analyzed by means of a calorimeter, spectrophotometer, etc.

Abstract: A testing elements for the calorimetric determination of oxidizable gas and/or vapor components in gas mixtures is provided. The testing element contains, besides usual oxidizing agents, at least one redox indicator, which is in the oxidized form. The redox indicator is preferably a benzidine derivative according to the general formula in which the radicals R are identical or different and denote a hydrogen, alkyl, aryl, halogen, trifluoromethyl, cyano, nitro, dialkylamino, ester, sulfoxyl ester, alkyloxy or aryloxy, X denotes a halogen, Y denotes a trifluoromethyl, cyano, nitro, dialkylamino, ester, sulfoxyl ester, alkyloxy or aryloxy, n is an integer from zero to three, and m equals 5−n. The testing elements are preferably designed as detector tubes that contain carrier materials, to which the oxidizing reagents and redox indicators are applied.

Abstract: The invention relates to a system and a method for detecting antifreezing substances in a hermetic compressor.

Abstract: In accordance with the present invention, there are provided articles for use in non-invasive measurements of nitric oxide levels in a variety of fluid media, e.g., in mammalian body fluids. Articles according to the present invention comprise a nitric oxide trapping agent contained within a vessel, wherein the vessel comprises a semi-permeable membrane. Nitric oxide diffuses through the semi-permeable membrane and is trapped therein for subsequent quantitative analysis. Articles of the present invention are particularly useful in selectively detecting nitric oxide in the presence of other NOx species.

Abstract: A system for measuring the concentration of gases using gas-selective indicator substances in a chip-like carrier (1) with an optoelectronic scanning device (2). The chip-like carrier (2) has composite partial elements (3, 4) wherein one partial element (3) contains channels (5) for guiding the gas in the carrier (1), and another partial element (4) has at least one multireflection element (6) for guiding light. Each multireflection element (6) is provided with a layer (7) with indicator substances, which layer faces the gases to be measured and reacts with same in a gas-selective manner. The optoelectronic scanning device (2) has at least one radiation source (21) with an associated radiation detector (22), which are in optical functional connection with each multireflection element (6).

Abstract: A gas-sensitive sensor membrane for the determination of gas concentrations in gas mixtures is proposed. Also proposed are a method and an apparatus for determining gas concentrations based on the change in the electromagnetic radiation absorption properties and/or the optical refraction index of an indicator substance, contained in the sensor membrane, which interacts with the gas to be determined.

Abstract: An airborne hazardous material reader device capable of receiving a collection element. The reader device has a body forming a slot area for receiving the collection element. The body has a crushing mechanism located within the slot area for breaking ampules attached to the collection element containing chemical testing reagents, a micro-pump positioned proximate to the slot area for controlling the temperature next to the collection element, a diode reading component incorporated within the body for distinguishing color changes from the release of chemical testing reagents from the broken ampules, an indicator for indicating the presence of a hazardous material when the diode reading component distinguishes color changes and a microprocessor that coordinates the sequence of the reader device. A method for airborne hazardous material detection also is disclosed.

Abstract: An indicator system provides a visual indication of the cumulative level of an airborne contaminant. The indicator is a transparent sheath with support medium having an acidic surface and treated with a color pH indicator. As a basic contaminant is adsorbed by the medium, the medium color changes. As additional contaminant is adsorbed, the color front progresses the length of the indicator. The indicator system may be used with an adsorptive filter system to predict the life of adsorption bed assemblies. A sample flow is taken upstream of the adsorption beds and is passed through the indicator. Preferably, the flow rate is calibrated so that the rate of the color change in the indicator is proportional to the rate of depletion of the adsorption bed. By monitoring the indicator, an accurate prediction of adsorption bed life may be made.

Abstract: The concentration of formaldehyde in air is measured by the method of the invention. More specifically, the invention relates to a method for analyzing formaldehyde in air by collecting the air and implementing an analysis of the concentration of formaldehyde at the site where such air is found.

Abstract: The slope lines of the peak lines are determined for a reference specimen and a test specimen and then compared with one another to analyze peak lines independently of the background. Preferably a minimum amplitude of a slope line is established with a threshold specimen so that fluctuations with a smaller amplitude can be disregarded. This method is suitable especially for automatic analysis of blot strips.

Abstract: The present invention provides a method by which harmful trace gases in a gaseous mixture containing as such harmful halogen gases, halogenated hydrogen gases, acid gases, oxidizing gases, basic gases, organic acid gases, especially halogen gases or halogenated hydrogen gases, are detected by using tetraphenylporphyrin (TPP) and quantitated from a calibration curve constructed therefrom, where the range of detectable concentration is made adjustable so that harmful gas can be detected and quantitated over a broad range of concentration. Furthermore, this invention also provides a method for extending the accessible range of gas concentration by adjusting the sensitivity of the detector material via control of tetraphenylporphyrin concentration in matrix polymer of the detector material, by controlling the gas concentration range via measurement at a specific wavelength(s), and by the use of a plurality of detector materials with pre-set assay sensitivity.

Abstract: A method and apparatus is disclosed for sensing hydrocarbon in the vapor path of fuel dispensers using a fiber-optic sensor. The sensor includes an absorber-expander sensing structure mechanically coupled to the fiber body and responsive to the presence of effluent fuel components for absorbing the hydrocarbon therein and expanding in response thereto. The expansion activity has the effect of generating a microbend deformation in the fiber, producing detectable changes in the optical throughput representing the concentration of hydrocarbon that is sensed by the absorber-expander element. The fiber-optic sensor is particularly useful in a vapor recovery system by providing an optical signal that is representative of the ambient hydrocarbon concentration.

Abstract: The concentration of a target gas is determined in an optical gas sensor system having an array of optical gas sensors wherein each sensor has a different sensitivity range for a target gas. An active sensor is selected from the array of optical gas sensors by determining which sensor has an optical transmittance value between 0% and 100%. Optical transmittance values of the active sensor are differentiated with respect to time. Concentration of the target gas is calculated as a function of both the rate of change of optical transmittance and the value of the optical transmittance at the beginning of the period over which the transmittance is differentiated. When a hazardous gas such as carbon monoxide is the target gas an alarm can be given when a threshold concentration is exceeded. Preferably, the transmittance values are converted to digital signals and processed in an eight-bit microprocessor to determine target gas concentration.

Abstract: A DMS detecting agent with a permanganate deposited on a support, characterized in that the support is quartz sand, and that the DMS detecting agent is obtained by adding an aqueous solution of silica sol or alumina sol and a permanganate to said quartz sand support for mixing and then drying the mixture, and a DMS detecting agent tube and a DMS detector tube using the same.

Abstract: For the purpose of determining the concentration c of an absorbing medium distributed homogeneously in a carrier, even if the film thickness d of the carrier is unknown, an absorbing medium is used whose measured absorption a(.lambda.) deviates from Lambert-Beer's law, in particular in the region of higher concentration, and n.gtoreq.2 model components of the absorbing medium are assumed, so thata(.lambda.)=(.epsilon..sub.1 (.lambda.).c.sub.1 +.epsilon..sub.2 (.lambda.).c.sub.2 + . . . .epsilon..sub.n (.lambda.).c.sub.n).d.The absorption a(.lambda..sub.i) is measured for at least n wavelengths, and the spectral absorption values .epsilon..sub.i (.lambda..sub.i) and concentrations c.sub.i of the model components are computed and the concentration c is determined from the functional relationship between the concentration c and concentrations c.sub.i of the model components c=f(c.sub.i), which relationship is obtained by calibrating measurements.

Abstract: Novel contrast media for use in ultrasonic imaging are described. Such contrast media may be comprised of an aqueous solution of one or more biocompatible polymers, wherein said biocompatible polymers are coated with and/or in admixture with at least one silicon containing compound. Alternatively, the contrast media may be comprised of an aqueous solution of one or more biocompatible synthetic polymers, or an aqueous solution of cellulose. The contrast media may be employed, if desired, with anti-gas agents and/or suspending agents.

Abstract: An indicator system provides a visual indication of the cumulative level of an airborne contaminant. An indicator has a transparent sheath with support medium treated with acid and a pH indicator, as the contaminant is adsorbed, the color changes along the medium. The indicator system may be used with an adsorptive filter system to predict the life of adsorption bed assemblies. A sample flow is taken upstream of the adsorption beds and is calibrated with a flow meter and valve. By monitoring the indicator, an accurate prediction of adsorption bed life may be made.

Abstract: The present invention provides a method by which harmful trace gases in a gaseous mixture containing as such harmful halogen gases, halogenated hydrogen gases, acid gases, oxidizing gases, basic gases, organic acid gases, especially halogen gases or halogenated hydrogen gases, are detected by using tetraphenylporphyrin (TPP) and quantitated from a calibration curve constructed therefrom, where the range of detectable concentration is made adjustable so that harmful gas can be detected and quantitated over a broad range of concentration. Furthermore, this invention also provides a method for extending the accessible range of gas concentration by adjusting the sensitivity of the detector material via control of tetraphenylporphyrin concentration in matrix polymer of the detector material, by controlling the gas concentration range via measurement at a specific wavelength(s), and by the use of a plurality of detector materials with pre-set assay sensitivity.

Abstract: The invention relates to a measuring process, the purpose of which is to increase the measuring accuracy of pulse oxymeters and comparable optical devices which are used in vivo to ascertain oxygen saturation of arterial blood. The measuring process according to the invention is provided for the purpose of ascertaining oxygenation of arterial blood in tissue by evaluating the differential light attenuation at several wavelengths. It is characterized by the fact that light attentuation of at least one wavelength is determined in order to choose those calibration curves of several variables (.OMEGA.1, .OMEGA.2. . . .) produced by different wavelength pairings with a minimized error in order to generate an output signal for the arterial blood oxygenation.

Abstract: Non-invasive methods have been developed for the measurement of NO levels in a variety of fluid media, e.g., body fluids. The present invention embraces the use of a semi-permeable vessel wherein said vessel contains an NO reacting substance to trap NO diffusing thereinto, and a simple physical or chemical detection method to measure the levels of the end products. Since NO is a neutral gas molecule, it is capable of diffusing freely across a wide range of biocompatible polymer membranes which exhibit a high permeability to NO and other neutral gas molecules, such as O.sub.2 and CO.sub.2, but which are not permeable to charged molecules, such as NO.sub.3.sup.- or NO.sub.2.sup.-. The latter two compounds are ubiquitously present in body fluids and often interfere with the measurement of NO levels. The permeability of selected membranes to NO, but not to NO.sub.3.sup.- or NO.sub.2.sup.

Abstract: Novel sensor devices composed of a crystalline colloidal array (CCA) polymerized in a hydrogel are disclosed. The hydrogels are characterized as being capable of shrinking and swelling in response to specific stimuli applied thereto. As the hydrogels shrink or swell, the lattice structure of the CCA embedded therein changes, thereby changing the wavelength of light diffracted by the CCA. Thus by monitoring the change in diffracted wavelength, the concentration of a stimulus is determined. The gels can be modified to sense numerous different stimuli. The sensor devices are specific in that they are modified to react with only one species or family of species. These sensors have various applications in areas including, for example, environmental and chemical systems, chemomechanical systems, sensor devices and medical diagnostic tools. Various methods for making and using these devices are also disclosed.

Abstract: A method for testing a non-hydrocarbon refrigerant, such as CFC-12 or HFC-134a, in a closed system for hydrocarbons, HCFC-22 refrigerant and ammonia is provided wherein a sample of the non-hydrocarbon refrigerant is withdrawn from the closed system, the pressure of the sample is measured and a metered portion of the sample is passed through a test apparatus (20) including a testing tube (30), a testing tube holder (40) for supporting the testing tube (30) and outfitted with a vent (48) to the atmosphere, and a pressure gauge (70) for indicating the pressure of the sample withdrawn. A medium (38) for indicating the presence of hydrocarbons in the sample flow passing through the testing tube is deposited on a surface disposed in the testing tube. The presence of undesired HCFC-22 refrigerant in the CFC-12 or HFC-134a is indicated by a higher pressure reading on the pressure gauge (70).

Abstract: The invention is a sensing method and an oxygen sensor for detecting a change of oxygen partial pressure in an ambient atmosphere. The sensor includes a sensing material selected from metal or its oxides which, when at an elevated temperature and exposed to a gas containing E a changing partial pressures of oxygen, is capable of changing from one metal or metal oxide phase to another such oxide phase and vice versa. Associated with such phase change is a change in a measurable physical property of the material. Heating elements, connectable to a power source, able to maintain a temperature gradient across said sensing material are necessary to maintain the material, during active sensing operation, in at least two of the phases defining a boundary line therebetween which is generally perpendicular to the longitudinal axis of the temperature gradient.

Abstract: The present invention relates to a process for indicating the presence of organic vapors comprising the steps of determining the color, absorption or emission spectra of a Pt--Pt double-complex salt of platinum or a neutral platinum complex in the absence of organic vapor, exposing said double-complex salt of platinum or a neutral platinum complex to a gaseous environment, determining the color, absorption or emission spectra of said double-complex salt of platinum or a neutral platinum complex after exposure to said gaseous environment, and comparing the color, absorption and/or emission spectra of said double-complex salt of platinum or a neutral platinum complex in the absence of organic vapor with the color, absorption and/or emission spectra of said double-complex salt of platinum or a neutral platinum complex after exposure to said gaseous environment to determine if there is a difference in the color, absorption and/or emission spectra.

Abstract: A method for determining a component of interest in a fluid, the method comprising four steps. The first step is to suspend a droplet or a film of a liquid. The second step involves contacting the fluid with the droplet or film. The third step involves diffusing at least a portion of the component of interest into the droplet or film to form an analyte. The fourth step involves determining the component of interest by analyzing the analyte. The fluid can be either a liquid or a gas. The analyte can be analyzed while in the form of a suspended droplet or film.

Abstract: A fiber optic chemical dosimeter system detects the presence of hydrazine fuels and nitrogen tetroxide and nitrogen dioxide gases that are used at rocket launch sites using colorimetric sensors that react selectively with the gases and then absorb laser light communicating through a fiber optic network having a conventional diode laser source transmitting interrogation pulses to a plurality of distributed sensors covering a wide area launch site, the sensor being reactive cladding or distal end types both providing optical reflective returns well suited for reflective near infra-red and visible-red laser interrogation by an optical time domain reflectometry monitor which compares the interrogated laser pulses with sensor returns to determine the extent and location of gas cloud exposures over the distributed wide area.

Abstract: A method is described for quantitative determination of mercury present in a sample (liquid or solid). The method involves converting mercury compounds to elemental mercury, removing all elemental mercury from the sample in vapor form by means of vacuum, passing the mercury vapor through a column which absorbs and captures all of the mercury vapor by converting it to a halide compound, eluting the mercury halide from the column, and colorimetrically analyzing for the amount of mercury halide collected.

Abstract: A diffusive sampler for effectively determining chemical vapor levels, the ampler having a thin pouch-like container made up of an impermeable back sheet and a selectively permeable front membrane attached thereto along its peripheral edges. The front membrane is made of a material capable of passing preselected vapors therethrough and for preventing other preselected vapors from passing therethrough and preferably has substantially the same permeation rate as human skin. Located within the pouch-like container is an adsorbent substance for adsorbing the chemical vapor and for providing information with respect to the chemical vapor levels adsorbed thereby. In use a plurality of the samplers are adhered to the skin of an individual wearing a protective garment to establish the effectiveness of the garment when subjected to specific chemical vapors.

Abstract: A laboratory reactor apparatus includes a suction tube, at least a portion of which has a constricted inside diameter. The lower portion of the suction tube is sealed to a sintered frit filter medium. The suction tube mounts in a reactor block into a reactor vial for receiving chemical components. An inlet channel with a first seal is formed through the block and conveys chemical component materials to the vial, and a suction channel with a second seal, coaxial with the suction tube, is used to remove resultant chemical compound materials therefrom. A pressurized gas channel containing inert gas is formed through the block to intersect the suction channel and the inlet channel.

Abstract: A first aspect of the invention involves placing a pair of parallel, spaced apart sealing septa in each channel of a reactor block through which materials are added to or removed from a reactor flask such that the septa enclose a cavity within the channel. A hole is formed through the block to intersect the cavity and is connected to a source of low pressure, substantially non-reactive gas which acts to prevent materials from leaking through a hole in either septum. The reactor flask is formed of glass as a substantially conical chamber with a first tube and a second tube connected to the flask perpendicular to its axis. The second tube extends within the flask so that its interior end resides proximate the opposite interior surface of the flask. The second tube terminates in a glass frit being permeable to certain of the chemical materials in work and non-permeable to others so as to act as a filter.

Abstract: A simple, convenient method is provided for measuring the concentration of a constituent of an aqueous fluid composition (e.g. aqueous machining fluid composition) and for measuring total alkalinity thereof.

Abstract: A gas detector, preferably for carbon monoxide detection, which includes a light detector(5), a light source (1) for providing a light beam which travels along a light path to the detector and detection chemistry (3) disposed in the light path for altering the light beam responsive to the impingement of a predetermined gas thereon. The detection chemistry includes a plurality of spaced apart members, each disposed in the light path. Each member includes a chemistry responsive to the impingement of the predetermined gas thereon for reversibly altering the light transmissive properties of the detection chemistry. The chemistry of any one of the members can differ from the chemistry of one or more of the other members if more than two members are present. The detection chemistry can, in part, act as a filter to light from the light beam. The detection chemistry is disposed in a gas ambient, the gas ambient being disposed between the spaced apart members.

Abstract: A fiber optic chemical dosimeter system detects the presence of hydrazine fuels and nitrogen tetroxide and nitrogen dioxide gases that are used at rocket launch sites using colorimetric sensors that react selectively with the gases and then absorb laser light communicating through a fiber optic network having a conventional diode laser source transmitting interrogation pulses to a plurality of distributed sensors covering a wide area launch site, the sensor being reactive cladding or distal end types both providing optical reflective returns well suited for reflective near infra-red and visible-red laser interrogation by an optical time domain reflectometry monitor which compares the interrogated laser pulses with sensor returns to determine the extent and location of gas cloud exposures over the distributed wide area.

Abstract: Diacetyl, especially resulting from spoilage of chilled red meat, is monitored by exposing an aromatic ortho-diamine at acidic pH to an environment containing, or possibly containing, diacetyl and detecting any change in absorption or reflection of electromagnetic radiation due to the ortho-diamine.

Abstract: There is provided a precisely quantitative measurement method of a hydrocarbonaceous polymerization inhibitor component in a fluorine-containing olefinic monomer, which inhibitor component is contained in the monomer in such a trace amount that it cannot be detected by a gas chromatography. In the method, an ultraviolet absorption spectrum of a concentrated sulfuric acid is measured after it is contacted with the fluorine-containing olefinic monomer and the concentration of the polymerization inhibitor is obtained based on an absorbance of the spectrum and a calibration curve which has been beforehand obtained.

Abstract: Novel contrast media for use in ultrasonic imaging are described. Such contrast media may be comprised of an aqueous solution of one or more biocompatible polymers, wherein said biocompatible polymers are coated with and/or in admixture with at least one silicon containing compound. Alternatively, the contrast media may be comprised of an aqueous solution of one or more biocompatible synthetic polymers, or an aqueous solution of cellulose. The contrast media may be employed, if desired, with anti-gas agents and/or suspending agents.

Abstract: A gas/liquid contact method and apparatus, for example, for oxygenating blood using O.sub.2 and O.sub.3. A low pressure stream of oxygen is introduced into a chamber through a spray orifice while inducing blood into the oxygen stream in a first blood/oxygen contact zone. The blood is caused to issue from the spray orifice as a dispersed low-pressure spray of blood droplets and is directed against a dome-shaped film forming surface located within the chamber in the path of spray. The droplets impinge on the surface at relatively low velocity and form a film for providing a further oxygen/blood contact zone. The apparatus may be designed to operate on a one-pass or a recirculation basis.

Abstract: Disclosed is an improvement to the method for the detection of creatinine in which creatinine, in aqueous solution, is contacted with a dry reagent system of an indicator for creatinine. The assay is carried out at a pH above about 11.5 which is maintained by an alkaline material. The improvement involves packaging the reagent system with a material capable of absorbing CO.sub.2 and at least some ambient water vapor. This inhibits the formation of carbonic acid thereby reducing the neutralization of the alkaline reagent system during storage to increase the shelf life and decrease the variability of the system.

Abstract: A fiber optic chemical dosimeter system detects the presence of hydrazine fuels and nitrogen tetroxide and nitrogen dioxide gases that are used at rocket launch sites using colorimetric sensors that react selectively with the gases and then absorb laser light communicating through a fiber optic network having a conventional diode laser source transmitting interrogation pulses to a plurality of distributed sensors covering a wide area launch site, the sensor being reactive cladding or distal end types both providing optical reflective returns well suited for reflective near infra-red and visible-red laser interrogation by an optical time domain reflectometry monitor which compares the interrogated laser pulses with sensor returns to determine the extent and location of gas cloud exposures over the distributed wide area.

Abstract: An apparatus for indicating the presence of CO and oil in a compressed breathing air supply provided in a tank. An indicator contains a substance which undergoes an observable physical change when exposed to a contaminant. The indicator is activated and placed in a housing and connected to the air supply and the indicator observed. In a preferred embodiment, the indicator is a single use indicator and contains an indicating gel in a glass tube which is opened by breaking at the time of use. Appropriate reference indicia are provided so the user may visually determine the contaminant level.

Abstract: A description is given of a method for the construction of a fiber-optic sensor in which a chromophore is fixed on a support and said support is linked to at least one optical fiber for the transmission and reception of a light signal. According to the invention, the end of the optical fiber (F) is heated and brought to a softening temperature, and the support (S) is immobilized on the optical fiber (F) by partially incorporating it in the softened portion of the optical fiber and subsequently cooling and solidifying the optical fiber.

Abstract: A method for measuring the presence of traces of substance in air by providing in a cuvette a substrate reacting with the substance by changing its opacity, passing at a defined flow rate air from the air body to be checked through the substrate, measuring the development of opacity. A portable apparatus comprises a housing (1, 101) holding a cuvette (131) containing a substrate (3, 103), an inlet tube (28) leading to the bottom of the cuvette, a pump (13) sucking air from the cuvette through a flow monitor (138) controlling the pump, a spectrophotometer lamp (19, 119) and a photo-diode (20) on opposite sides of the cuvette (131), a monitor monitoring the level (4, 104) of the substrate in the cuvette, and a monitor (23, 123) monitoring the temperature of the substrate, a computer (24) receiving signals from the photodiode (20), the level monitor, and the temperature monitor to calculate a temperature and level compensated indication of the substrate opacity.