Abstract: An oxygen sensor is provided for determination of the partial pressure of oxygen. In one aspect, the invention consists of oxygen-quenchable luminescent lanthanide complexes for an oxygen sensor. The complexes are oxygen-quenchable even though immobilized in a solid matrix, such as a solid polymeric matrix, and preferably are terbium complexes of Schiff base or .beta.-diketone ligands. Certain preferred processes are described for improving the oxygen sensitivity of the lanthanide complexes. In another aspect, the invention consists of a combination measuring and reference analyte sensor containing both quenchable and nonquenchable luminescent materials. The materials luminesce at different wavelengths and thus may be transmitted together down a single optical fiber and later descriminated by means of filters and separately detected. In a third aspect, the invention consists of a low-noise phosphorescent analyte sensor employing a gatable detector.

Abstract: In order to obtain a higher measuring accuracy and better selectivity in the optical quantitative analysis of sulphur dioxide in gaseous or liquid media, it is proposed that the medium to be analyzed be brought into contact with a fluorescent indicator which emits fluorescent light upon excitation and which is from the group of triphenylmethane dyes, and that the extent to which fluorescence is quenched by the SO.sub.2 quencher be used as a measurable variable for quantitative determination of the content of sulphur dioxide in the medium.

Abstract: An optical sensor which is a gas permeable silicone polymeric matrix having at least one optical indicator therein for providing an optical signal in response to excitation light. The optical indicator essentially comprises a mixture of non-polar derivatives of a polynuclear aromatic compound.

Abstract: A propellant sample combustion apparatus employing a multiply optical ported pressure vessel for sample illumination, sample viewing, and sample burn face elevation is described. High-speed motion picture filming using short-duration high-intensity laser provided optical illumination from a copper-vapor laser is employed. Details of the employed pressure vessel, a burn inhibiting coating for the propellant sample, a laser coherence spoiler, and a sample level maintaining closed-loop apparatus are also disclosed.

Abstract: A device for analyzing the composition of the exhaust gas of an internal combustion engine in which a light source provides a light beam absorbable by the exhaust gas, and a plurality of measurement cells are traversed by radiation of the light beam while the exhaust gas flows through the cells. A corresponding number of radiation detectors are arranged after the measurement cells to receive the absorption attenuated light radiation and to produce an electrical measurement signal. At least one light interrupter periodically interrupts the light radiation.

Abstract: A carbon monoxide detector comprises a single monochromatic infrared source which is arranged to alternately direct light through two separate gas-containing test chambers. The first chamber is supplied with gas to be tested which has an unknown carbon monoxide content. A catalytic burning chamber is connected between the first and second chambers to receive gas from the first chamber, burn the carbon monoxide in the gas to carbon dioxide and supply the carbon monoxide free gas to the second chamber. A single infrared light detector is provided for receiving light as it comes alternately from the two chambers. The light from the two chambers is compared to determine the amount of carbon monoxide present in the gas of the first test chamber. Since the same background gas is provided in both chambers and only a single infrared source and detector are utilized, inaccuracies due to differences in background detection, infrared source intensity and infrared detector sensitivity are overcome.

Abstract: Chemiluminescence is detected in a luminol solution free of metal ions flowing through a porous material to indicate the presence of certain nitrogen-containing gases. Continuous monitoring of atmosphoric gases is possible through use of the described methods and related apparatus.

Abstract: A gas sensing apparatus suitable for repeatedly sensing the partial pressure of a selected gas in a gaseous mixture is accomplished by employing optical detecting means. A sensing material having a light reflective surface reversibly reacts with a sensed gas in accordance with a temperature-sensed gas partial pressure relationship to cause a predictable change in reflectivity of the light reflective surface. The chemical reaction between the sensing material and sensed gas is reversible, therefore allowing quick, precise and repetitive sensed gas partial pressure determinations.

Abstract: The presence of certain chemicals on the emitting surface of the surface-derivatized photoluminescent semiconductor alters the characteristics of radiation emitted from said surface. This alteration is used to indicate the presence of those chemicals in the environment.

Abstract: The presence of certain chemicals on the emitting surface of the surface-derivatized photoluminescent semiconductor alters the characteristics of radiation emitted from said surface. This alteration is used to indicate the presence of those chemicals in the environment.

Abstract: Thin films of hygroscopic, halogenated organic polymer having pendant groups of a relatively strong acidic type (e.g., sulfonic groups) and pendant groups of a relatively weak acidic type (e.g., carboxylic groups) are employed for humidity sensing by electronic, acoustic, and optical techniques.

Abstract: The present invention relates to a novel method and apparatus which can provide continuous monitoring of the oxygen content of a gas over an indefinite period of time and at a minimal cost.In the novel apparatus of the present invention, a light source and a light sensitive detector are disposed within the atmosphere to be measured, and a polymeric film formed from a manganese tertiary phosphine polymer complex is deposited between the light source and the detector. As oxygen pressure increases or decreases a change in color intensity of the film takes place which controls passage of light from the light source to the detector. The detector in turn is suitably connected to an audio and/or visual warning device and/or a recorder which will provide the desired form of warning.

Abstract: Reactive gases like, for example reducing gases, specifically carbon monoxide, are detected in a gas mixture, particularly in air, with extremely high sensitivity and with high precision using a gas detector in which the attenuation of the intensity of an infrared radiation beam by a catalyst layer is utilized. Such catalyst layer contains at least one transition metal selected from at least one of the groups I, VII, and VIII of the Periodic Table of the Chemical Elements. Preferably, chemical elements are used having an atomic weight in the range of about 100 to about 205. The detection of carbon monoxide is particularly sensitive using a catalyst layer which substantially contains a metal capable of forming a carboncarbonyl compound with carbon monoxide.

Abstract: A gas sensor comprising a device by which photo absorption is changed in the presence of hydrogen gas or hydrogen containing compound gas and an optical detecting means for detecting the change of photo absorption. The device is provided in the form of a laminate made of a metal adsorbing and dissociating hydrogen or hydrogen containing compound gas and a solid compound which is reduced by hydrogen atoms produced in the metal to change photo absorption.

Abstract: In an optical sensor used mainly for determining the partial pressure of O.sub.2 or CO.sub.2 in respiratory gas includes a sample measuring chamber through which sample medium to be analyzed flows or into which it is fed, a reference measuring chamber containing a reference gas or a reference liquid of constant composition, a light source, a unitary excitation filter positioned between the light source and first sides of both the sample measuring chamber and the reference measuring chamber, a single fluorescent sensor element on the second sides of both the sample measuring chamber and the reference measuring chamber, and first and second detectors for detecting the fluorescence radiation from the fluorescent sensor element respectively based on the light passing thereto from the sample measuring chamber and the reference measuring chamber.

Abstract: A device for measuring the absolute value of the density of salts in the atmosphere including: an airtight water tank containing super pure water, a device for supplying super pure water to the airtight water tank, an elongated cylindrical pipe for bubbling a predetermined quantity of air from the atmosphere into the super pure water of a predetermined quantity, from inside the airtight water tank, an outlet for exhausting the super pure water in the airtight water tank after the bubbling, a sodium ion analyzer for measuring the density of sodium ions in the exhausted super pure water, and a background value measuring device including the sodium ion analyzer for measuring the density of sodium ions in the super pure water at the water supplying means while bubbling. Another device for measuring the absolute value of the density of salts in the atmosphere further includes a device for washing the airtight water tank by super pure water after the exhaustion of the super pure water in the tank.

Abstract: Offset-error included data normally is output from a single ramp analog to digital converter in response to input information applied thereto during light or cuvette sample intervals. During dark sample intervals between the cuvette sample intervals, the input information is blocked from the converter and the converter is operated with the output counter counting down to a dark count representing the offset error of the counter. During the next cuvette sample interval the counter counts up from the dark count effectively subtracting out the offset error introduced by the converter.

Abstract: An optical sensor comprising a selectively permeable matrix of hydrophobic material and a plurality of hydrophilic beads dispersed in the matrix. At least some of the beads carry an optical indicator. The matrix is capable of transmitting light at least at selected wavelengths from outside the matrix to the beads.

Abstract: Effluent from an LC is passed through a thermospray nozzle which flash vaporizes substantially all of the solvent while directing any sample components as a collimated beam onto a moving tape so that the various components form spots on the tape. The tape is moved along a path that intercepts the optical path of an FTIR spectrometer whereby IR energy from the spectrometer is passed through each sample component and is then spectrally analyzed. The tape can be wound up, stored, and later used for further analysis of the spots, as desired, in the FTIR spectrometer.

Abstract: A device for detecting small amounts of a chemical such as ammonia, and other ammonia-like molecules such as hydrazine or pyridine, in air and in other gases is disclosed. A capillary tube serves as a multiple total reflective medium for an optical beam from a light-emitting diode. The outer surface of the capillary tube is coated with a dye which, when exposed to the chemical, changes color so that the multiply reflected light is modified. The resultant change in the output light intensity from the capillary tube is photodetected and recorded to sense the presence of the chemical. When the chemical is removed, the dye returns to its original color so that the device can be reused.

Abstract: A flame detector analyzer of the type wherein a sample gas is introduced into a flame formed by burning a fuel gas in presence of a combustion supporting gas, comprises a background providing device for supplying a background component gas capable of emitting a characteristic spectrum having the same wave length as that of the characteristic spectrum of a measuring object component contained in the sample gas, the light spectrums emitted from the measuring object component and the background component gas being received and treated to be detected, thereby increasing the measuring accuracy for the measuring object component and improving the resolving power at a low concentration detection region.

Abstract: According to the present invention volatile hydrides such as diborane, arsine, phosphine and the like are made to react with mercuric oxide at room temperature to produced mercury atom, the concentration of which is thereafter measured and the concentration of volatile hydrides is determined in accordance with the corresponding measured mercury atom concentration. As the measuring apparatus according to the present invention is made to measure mercury atom, it can easily detect even extremely small quantity of substances such as volatile hydrides and respond quickly, thus enabling the apparatus to be suitably used as a monitor in semiconductor industry.

Abstract: An ammonia gas analyzer and a sulfuric acid converter utilized in the ammonia gas analyzer in which a sample gas is maintained at a relatively high temperature prior to entering the sulfuric acid converter to thereby prevent acidic sulfuric acid sulfates and/or ammonia sulfates from crystallizing and being deposited on the walls of the device. The ammonia gas analyzer includes gas sampling means, a gas measuring channel connected to the gas sampling means, a comparison gas channel connected parallel to the measuring gas channel with the measuring gas channel including an NH.sub.3 /NO converter for converting NH.sub.3 in a sample gas into NO and means for measuring a concentration of NH.sub.3 on the basis of variations of an amount of NO in the measuring gas channel with respect to that in the comparison gas channel.

Abstract: Apparatus for detecting the concentration of a gas by measuring the amount of mercury vapor generated when the gas is passed through a mercuric oxide bed. The apparatus includes a body having a central bore therein with a quartz rod at one end for directing ultraviolet light from a source through the central bore. A second quartz rod at the opposite end of the central bore directs the ultraviolet light to a detector coupled to an electronics circuit for analysis purposes. A fitting coupled to the body has a gas inlet port and a passage from the port to the central bore of the body. The mercuric oxide bed is across the passage so that the gas, in passing through the bed, causes mercury vapor to be generated and to pass into the central bore of the body. The amount of mercury vapor is measured by its spectral absorption in the ultraviolet range when the mercury vapor is in the central bore of the body.

Abstract: A fluorescent sulfur dioxide analyzer that includes a generator for producing a standard gas of known sulfur dioxide content. A source of ultraviolet radiation illuminates the interior of a reaction chamber in which an oxygen containing gas is passed over a deposit of sulfur. During passage, a part of the oxygen reacts with the sulfur to produce sulfur dioxide. Because the quantity of sulfur dioxide is predictable and reproducible, the resulting sulfur dioxide containing gas is suitable for use as a standard or span gas in the analyzer with which it is used, thereby eliminating the need for the storage tanks or permeation tubes.

Abstract: A method of determining if an internal combustion engine has been operated on a leaded fuel. The method has the following general steps. A misfueling detector is formed from a material which is capable of interacting with lead when exhaust gases containing lead are passed thereover. The interacting lead alters at least one measurable characteristic of the misfueling detector. The misfueling detector is placed in an exhaust system and exhaust gases from an internal combustion engine are allowed to pass thereover. The misfueling detector is removed from the exhaust system and the measurable characteristic thereof is measured to determine whether or not the misfueling detector had absorbed lead therein while located in the exhaust system of the internal combustion engine.

Abstract: Colorimetric measuring arrangement comprising a reaction chamber in which the gas to be measured is absorbed in a reaction liquid and enters into a color reaction. The reaction chamber is in the form of an atomizer in which the reaction liquid is atomized into very fine droplets and thus provides a large surface for the adsorption of gas. The reaction chamber is adjoined by a separation pipe in which the gas phase is re-separated from the reaction liquid. The separation pipe communicates through a liquid guide with an inlet funnel which opens into a micro-throughflow cell. The outlet of the micro-throughflow cell is connected to a siphon. These measures avoid troublesome pulsations in the micro-throughflow cell.

Abstract: Process and apparatus for measuring total fixed gaseous nitrogen species, including NH.sub.3, NO, NO.sub.2, HCN and organic amines in gaseous mixtures. The process involves catalytic conversion at elevated temperature of all fixed nitrogen species to nitric oxide, NO, followed by chemiluminescent measurement of the resulting NO concentration. The improvement features of the process are the use of a reduced pressure gaseous sample flow to prevent N.sub.2 poisoning of the heated platinum catalyst and a preheat step of the reduced pressure gaseous mixture in an inert, non-catalytic quartz preheater prior to catalytic conversion to prevent loss of some species, such as NH.sub.3, through premature catalyzed reaction with NO and subsequent loss from the system as N.sub.2.

Abstract: A flame-photometric detector burner of a gas chromatograph employing a system of two nozzles arranged in relation to each other for securing mutual flame jump-over from one nozzle onto the other one, and vice versa. One nozzle is designed to supply carrier gas with the substance to be analyzed, and the other is designed to only supply an oxidizer. The outlets of both nozzles are arranged within a hydrogen stream in a cavity of a combustion chamber of a detector block. The nozzle where only the oxidizer is supplied can be electrically insulated from the detector block, and connected to a high-voltage source.

Abstract: A method and an apparatus for photometrically analyzing a stream under test containing both chlorine and chlorine dioxide is characterized by heating a portion of the stream to decompose any chlorine dioxide therein into elemental chlorine. This heated portion of the stream is photometrically analyzed to determine the concentration of chlorine produced by the decomposition of chlorine dioxide, taking into account the concomitant dilution produced thereby.

Abstract: The concentration of a substance of interest is measured by exposing a peable-membrane face of an indicator chamber containing an indicator to the substance, monochromator radiation being incident upon the indicator through a transparent wall of the indicator chamber, the exiting radiation being received by a light-metering unit for ascertainment of the effect upon the indicator's absorbence of fluorescence of the substance of interest. The indicator substance is additionally exposed to a reference substance of known concentration which is permitted to engage the indicator substance by diffusion through such permeable membrane, in order that the indicator be calibrated.

Abstract: A technique is described for continuously detecting or measuring a gas such as hydrogen cyanide in a gas stream. The gas stream is passed in counterflow relationship with a well defined stream of gas absorbing reagent liquid in an absorption cell through which the reagent flows under gravity feed. The exposed reagent is passed through a heater in which the color of the reagent is developed. The reagent is passed through the heater at a constant regulated flow rate with a flow controller operative between the absorption cell and the heater to provide a consistent color development. A stable and consistent detection and measurement of the amount of hydrogen cyanide in the gas stream is obtained.

Abstract: A method and apparatus for determining the level of sufuric acid in atmospheric air which also contains other interferrants, including a sampling cycle to collect sulfuric acid on the walls of a collection chamber tube which is cooled, while at the same time eliminating interfering sulfur dioxide and ammonia by treating them with a dilute flow of hydrochloric acid through the collection chamber, and further including an analysis cycle during which the walls of the collection chamber tube are heated so as to revolatilize the sulfuric acid and entrain it in a clean air stream which then passes to the burner block of a flame photometric detector, the clean air stream being saturated with water vapor to make the revaporization of sulfuric acid more rapid and complete.

Abstract: In a sulfur dioxide fluorescence analyzer, a method and apparatus for eliminating the fluorescence effects of nitric oxide is disclosed wherein a sample gas is mixed with a diluent which substantially quenches nitric oxide fluorescence.

Abstract: In a sulfur dioxide analyzer which measures the content of sulfur dioxide by fluorescence of sulfur dioxide molecules when illuminated by an ultraviolet light source, there is disclosed a converter containing vanadium pentoxide for removal of polynuclear aromatic hydrocarbons which produce interference when sulfur dioxide is measured by fluorescent methodology.

Abstract: A device and method for measuring the concentration of a gas carried in a medium such as air comprising, an indicator tube having material therein which progressively changes color along its length as it is exposed to the gas to be measured. A flow device is connected to the indicator tube for drawing or pushing the carrier with gas therethrough to cause the progressive change in color in the indicator tube material. A light barrier in the form of a light source and detector facing each other and on either side of the indicator tube is provided and mounted to slide along the axis of the indicator tube and in a direction of propagation of the progressive color change. A reference light barrier is provided in the area of the indicator tube which is not exposed to the progressive color change to produce a reference signal which is compared to a signal produced by the movable light barrier.

Abstract: An apparatus for detecting the presence of a specific substance in a gas stream is disclosed.

Abstract: A flame head for a flame photometric detector is disclosed comprising an explosion-proof housing having a combustion chamber therein defined by a fused quartz tube flame wall barrier. Means are provided for securing a fiber-optic bundle to the housing with one terminal end of the fiber-optic bundle positioned adjacent the fused quartz tube whereby light emitted from the combustion chamber can be transmitted via the fiber-optic bundle to a photomultiplier and associated electronic detection means remotedly located therefrom. A burner tip communicates with one end of the fused quartz tube and provides gas effluent and fuel through a passage therein coaxially aligned with the quartz tube while providing required air to four circumferentially spaced ports disposed about the passage. Means are also provided for purging fuel from the area immediately adjacent the terminal end of the fiber-optic bundle adjacent the quartz tube.

Abstract: The specification describes a method for the continuous quantitative indication of pollutants in air, in which a reagent solution taken from a storage container is first passed through the reference cell of a photometer, is then mixed in a reaction chamber with the gas to be examined and, dependent on the concentration of the pollutant, is decolorized or colored, is then passed through the measuring cell of the photometer, and is finally collected in a collection container, an indication corresponding to the concentration of pollutant being derived from the output of the photometer, and in which the reagent solution leaving the measuring cell and containing the pollutant is once again supplied to the reaction chamber and produces a more intensive reaction.