Abstract: Gases flow to individual gas analysis cells. The cells are sequentially aligned with an infrared detector, which senses the composition and quantities of the gas components. Each elongated cell is tapered inward toward the center from cell windows at the ends. Volume is reduced from a conventional cell, while permitting maximum interaction of gas with the light beam. Reduced volume and angulation of the cell inlets provide rapid purgings of the cell, providing shorter cycles between detections. For coal and other high molecular weight samples, from 50% to 100% oxygen is introduced to the tubes. Cells are suspended from adjustable holders on a frame which is spaced from a table. The table is moved by a linear motor and a fixed platen. Sides of the table are shielded to prevent electromagnetic and magnetic motor interference with detected results. The entire table, cells, mounting plate and linear motor are mounted in a housing with aligned holes for the analysis energy source and detector.

Abstract: An opto-electronic sensor for recognizing transparent articles, such as, for example, glass bodies, plastic bodies, or foils. The sensor includes at least one transmitter for transmitting light signals into a monitored region, at least one receiver for receiving the transmitted light signals, and at least one evaluation unit for the evaluation of the received signals. The transmitter is designed for the transmission of the light signals in the UV range. At least one reference transmitter is provided for the transmission of light signals into the monitored region. The light signals transmitted by the reference transmitter lie in a different frequency range from the light signals transmitted by the transmitter.

Abstract: A method and an apparatus for monitoring and controlling a characteristic of process waters or effluents from wood pulp bleaching, pulping and paper making processes utilizing a bleaching agent such as hydrogen peroxide (H.sub.2 O.sub.2), Na.sub.2 S.sub.2 O.sub.4, ClO.sub.2, Cl.sub.2 or O.sub.3 or a pulp delignification process utilizing a delignification agent such as NaOH, Na.sub.2 S, O.sub.2, Na.sub.2 SO.sub.3, and enzymes including ligninase, xylanase, mannanase, laccase, and peroxidase are disclosed. This is done by obtaining at least three measurements of ultraviolet-visible light from the effluent by taking a first measurement measured at a first wavelength, a second measurement measured at a second wavelength, and a third measurement at a third wavelength, formulating two ratios from the three measurements and using the ratios for computing an empirical value of the characteristic of the effluent.

Abstract: Method and apparatus for measuring the quantity of sample materials which provides stable measurements for extended periods of time. A source beam containing measuring radiation and reference radiation is directed through a sample material. The measuring radiation consists of spectral energy that interacts substantially with the sample material. The reference radiation consists of spectral energy with substantially different interaction properties with the sample material. Radiation is directed along separate analyzing and normalizing information channels wherein the radiation has substantially different sample interaction. Analyzing and normalizing detectors provide responses to radiation in respective analyzing information channel or normalizing information channel. A measuring mode is established by inserting a first filter into the source beam to allow substantially only measuring radiation to propagate to the detectors, creating measuring responses.

Abstract: A gas monitor includes an infra-red source enclosed within a housing having inner surfaces which are reflective. Radiation emitted from the source reflects off ellipsoidal surfaces and intermediate planar surfaces to be focussed at a sensor, being reflected five times. Radiation is absorbed by gas within the housing and a comparison of the source intensity and detected intensity gives a measure of the gas concentration. Use of ellipsoidal reflective surfaces directs emitted radiation along a plurality of routes having substantially the same path length, hence giving an accurate measure of the gas concentration with a compact device. In another embodiment, off axis parabolas are used to direct the radiation through the gas.

Abstract: Disclosed are photometric methods and devices for determining optical pathlength of liquid samples containing analytes dissolved or suspended in a solvent. The methods and devices rely on determining a relationship between the light absorption properties of the solvent and the optical pathlength of liquid samples containing the solvent. This relationship is used to establish the optical pathlength for samples containing an unknown concentration of analyte but having similar solvent composition. Further disclosed are methods and devices for determining the concentration of analyte in such samples where both the optical pathlength and the concentration of analyte are unknown. The methods and devices rely on separately determining, at different wavelengths of light, light absorption by the solvent and light absorption by the analyte. Light absorption by the analyte, together with the optical pathlength so determined, is used to calculate the concentration of the analyte.

Abstract: Apparatus for the optical detection of selected toxic gases, using the ultraviolet region of the electromagnetic spectrum, and the known absorption properties of the toxic gases in the ultraviolet region. An ultraviolet flashlamp source illuminates a straight, highly polished metal tube with numerous perforations to permit access for the gas to be detected. The ultraviolet light then enters an optical compartment comprising an optical beamsplitter and two ultraviolet detectors with wavelength selective narrowband filters attached. The filters are selected so that one overlaps the region of absorption by the gas while the second is in a region where there is no absorption by the gas. The electronic circuit following the ultraviolet detectors and the drivers for the flashlamp, are timed by a microprocessor that provides the means for the electronics and data processing to be synchronized with the flashlamp pulse.

Abstract: One or both of two methods and systems are used to determine concentration of a known material in an unknown mixture on the basis of the measured interaction of electromagnetic waves upon the mixture. One technique is to utilize a multivariate analysis patch technique to develop a library of optimized patches of spectral signatures of known materials containing only those pixels most descriptive of the known materials by an evolutionary algorithm. Identity and concentration of the known materials within the unknown mixture is then determined by minimizing the residuals between the measurements from the library of optimized patches and the measurements from the same pixels from the unknown mixture. Another technique is to train a neural network by the genetic algorithm to determine the identity and concentration of known materials in the unknown mixture. The two techniques may be combined into an expert system providing cross checks for accuracy.

Abstract: An ultraviolet transmittance analyzer for fabrics, translucent packaging, sunscreen products and the like using an internally pulsed white-light illuminated integrating sphere, exiting sample and reference diffusely reflected beams, and applying them respectively to separate sample and reference spectrographs with light detector arrays.

Abstract: A device for detecting fluorescence generated in a sample medium in a cuvette tube irradiated with light for analysis purposes. The device includes a main element comprising a light source, an optical element mounted on the cuvette tube in optical contact therewith, and a photodetector. The light source is placed on the outside of the cuvette tube so as to send light into the tube in a direction essentially transversely to the longitudinal axis of the tube. The refractive index of the optical element is essentially the same as the refractive index of the wall of the cuvette tube. The photodetector functions to detect fluorescence light which falls on the detector after having passed in the cuvette tube via the optical element.

Abstract: The present invention relates to a system, apparatus, and process to reduce the oxidized mercury in an exhaust gas to elemental mercury and to prevent its reoxidation by congeneric components in the exhaust gas prior to the photometric measurement of said elemental mercury. In the process, the sample stream flows through a reactor heated to preferably about 800.degree. C. in which a stream of hydrogen is introduced directly into a hot portion thereof. The congeneric oxidized mercury species, i.e, HgCl.sub.2, and HgO are thermally reduced quantitatively to elemental mercury. The hydrogen reacts in situ with oxygen to form water vapor and with chlorine to form hydrochloride gas. The hydrochloride gas is effectively absorbed by the water vapor and consequently prevents the reoxidation of elemental mercury. The concentration of total mercury in a stream can then be determined by the intensity of radiation absorbed by a UV spectrometer.

Abstract: The invention relates to a system for checking a suspension of solid particles, having a test tube for taking up and sedimentation of the suspension, having--an illuminating radiation source (L),--a test tube (P) is transparent to the illuminating radiation and the radiation emerging thereof, in which test medium is allowed to sediment and which can be located in the radiation path of the system,--optionally, a further test tube (PE), that is transparent to the illuminating radiation and the radiation emerging thereof, in which a reference or calibration liquid is allowed to sediment and which can be located in the radiation path of the system,--a sensor device to detect the illuminating radiation (S.sub.L)--a sensor device for detecting radiation emerging by transmission (S.sub.T) from the test tube(s) (P.sub.E, P)--a sensor device for detecting the radiation (S.sub.F) emerging from the test tube(s) at an angle other than 180.degree.

Abstract: An apparatus for measuring characteristics of a liquid including a channel through which, during operation, the liquid flows and a plurality of sensors for measuring characteristics of the liquid as it flows through the channel. The cross-sectional shape of the channel varies along its length, but the cross-sectional area of the channel is substantially constant so that, during operation, liquid flows through the channel at a substantially uniform speed. The sensors include an ultra-violet sensor and an infra-red sensor, each having a source and a detector of electromagnetic radiation arranged along an axis transverse to the channel. The axes of the two sensors are transverse to each other.

Abstract: A photoionization detector includes a brittle substrate having a void micromachined therein with a void inlet and a void outlet. First and second electrodes are disposed in the void. An ultraviolet transparent member covers at least a portion of the void in which the electrodes are disposed. A gas sample passes through the void and is exposed to ultraviolet radiation from a UV source. Ionization of the sample is measured as current flowing between the electrodes.

Abstract: A method, an apparatus, and an integrated system using the apparatus for measuring a concentration of odorant in odorized gas which is produced by adding the odorant to un-odorized gas comprised mainly of hydrocarbon gas. In a detection absorbance measuring step, there is obtaining detection odorized gas absorbance which is absorbance of the odorized gas relative to a detecting ultraviolet light having high absorbability to the odorant and low absorbability to the un-odorized gas. In a subsequent concentration deriving step, the odorant concentration in the odorized gas is derived from the detection odorized gas absorbance.

Abstract: In a first embodiment of the invention, a method for determining the hydrogen-to-carbon ratio of a liquid hydrocarbon fraction is presented. A sample of the liquid fraction is subjected to an ultra-violet absorption analysis. The results of the analysis correlate directly to the hydrogen-to-carbon ratio of the hydrocarbon fraction and, with a knowledge of this correlation, the hydrogen-to-carbon ratio of the sample under analysis may be determined. Another embodiment provides a method for monitoring the performance of a process for the preparation of olefins by the thermal cracking of a hydrocarbon feedstock. A liquid fraction is recovered from the product of the thermal cracking and subjected to an ultra-violet absorption analysis. The result of the analysis correlates directly to the hydrogen-to-carbon ratio of the product, which in turn correlates to the cracking severity being applied in the thermal cracking process.

Abstract: The detection of fractures in diamonds which are filled with high index of refraction glass is easily and quickly carried out by observation under ultra violet light. Such light having a wavelength between 300 and 400 nm, as reflected from, or transmitted through, such diamonds is imaged using a CCD camera, or directly by the use of fluorescent conversion to the visible spectrum. In either approach, the fracture fills are clearly and immediately distinguishable.

Abstract: A spectrometric gas measurement apparatus for the determination of the presence and/or concentration of gases in a spatial region has a spectrometric measurement head which transmits into the spatial region measurement radiation having the spectral ranges necessary for the determination of the gases. Furthermore, a reflector is provided at the spatial region which reflects the light which is passed through at least a part of the spatial region back to the measurement head where it is split up spectrally in an analyzer and then supplied to a photoreceiver arrangement. A measurement tube extending in the direction of light propagation is provided in the spatial region through which the measurement light passes.

Abstract: A gas analyzing apparatus includes a sample gas line with a sample line valve for providing a sample gas, and a reference gas line with a reference line valve for providing a reference gas. A first gas analyzer is connected to the sample line downstream of the sample line valve, and a second gas analyzer is connected to both the sample and reference gas lines downstream of the valves. The lines are configured such that sample gas and reference gas may be alternately provided to the second gas analyzer either directly or indirectly via the first gas analyzer.

Abstract: The present invention relates to methods and means including a process and system for producing an elemental-mercury-free reference flue gas which is used to obtain background photometric measurements thereby eliminating the photometric interferences of flue gas components to the photometric measurement of mercury. In the process, elemental mercury is selectively removed from a portion of a gaseous stream (the reference portion) and the intensity of radiation absorbed is measured by a UV spectrometer on the resulting mercury-free reference gas, and thereafter the concentration of mercury in the remainder of the gaseous stream is determined through utilization of the ratio of the transmitted radiation of the mercury-containing flue gas with respect to that of the mercury-free reference portion of the gaseous stream. The mercury concentration can then be determined without interference by other absorbing moieties at 254 nm in the flue gas.

Abstract: A photometer for measuring electromagnetic radiation absorption of a sample utilizing a source of the electromagnetic radiation. Electromagnetic radiation is conducted from the source, to a sample sensor, and is passed through the sample utilizing a sample cell. The electromagnetic radiation is then directed to a detection system which determines absorbance of electromagnetic radiation by the sample at the sample cell. The detection system includes a beam splitter which receives the electromagnetic radiation and outputs first and second beams. A first detector having a first wavelength filter and a second detector having a second wavelength filter receives the two beams from the splitters. One detector may be employed to produce a reference signal. The remaining detector or detectors produce an output signal which is a representation of a characteristic, such as absorbance of the sample. The output signals are operated on by a reference signal, and converted into a measurement absorbance.

Abstract: An emission-concentration monitoring system (20)includes first and second monitor stations (22,32) which are separated by a sensing space (40) along a path (28) of a moving vehicle (26). Each station has a source of electromagnetic radiation (64) which is directed through the vehicle's exhaust plume. Each station also has a set of detectors (66) which are positioned to receive the radiation and configured to measure transmittances at wavelengths which are absorbed by molecular species of exhaust plume (e.g., hydrocarbons, nitric oxide, carbon monoxide and carbon dioxide). These sensed transmittances are converted to emission concentrations by a data processor (50) and compared to a set of emission-concentration standards. The vehicle is determined to be in violation only if its emission concentrations at both the first and second monitor stations exceeds the standards.

Abstract: An ultraviolet light source is provided on one end of a cell into which a sample gas is introduced. A beam splitter for dividing beams which have been transmitted through the cell into two optical paths is provided on the other end of the cell. A first detector is provided in one optical path, and a second detector is provided in the other optical path. A gas filter filled with a component to be measured is positioned between the detectors and beam splitter so that a concentration of the component to be measured may be obtained on the basis of a difference between the output of the first detector and the product of the output of the second detector and an appointed constant. Influences resulting from components coexisting in the sample gas are reduced. Alternatively, an infrared light source may be provided on one end of a sample cell. A gas filter filled with a gas the same as the gas to be measured is provided at the other end of the sample cell.

Abstract: A mercury monitoring device that continuously monitors the total mercury concentration in a gas. The device uses the same chamber for converting speciated mercury into elemental mercury and for measurement of the mercury in the chamber by radiation absorption techniques. The interior of the chamber is resistant to the absorption of speciated and elemental mercury at the operating temperature of the chamber.

Abstract: A spectroscopic system for the analysis of small and very small quantities of substances makes use for the purposes of energy transfer of cone-shaped aperture changers (14, 15) which are arranged in the object zone (8) between the light source (L) and the sample (9) and, during absorption measurements, also between the sample (9) and the inlet slot (3) of a spectrometer (1). If the form used is a double cone, the aperture changers (14, 15) facilitate an oblique coupling in a capillary tube accepting the sample (9) which acts as a step-waveguide for the coupled radiation.

Abstract: The in-situ monitoring of metalorganic precursor delivery in a metalorganic chemical vapor deposition oxide system in high temperature super conductors (HTSC) film growth is accomplished by utilizing the distinct absorbance bands for metalorganic compounds. As an ultraviolet-visible light beam is passed through an effluent metalorganic gas stream the relative change in ultraviolet-visible absorbance of the ultraviolet-visible light beam passing through the effluent metalorganic gas stream is monitored. Stoichiometry control is achieved by feeding back absorbance data to a controlling parameter such as carrier gas mass flow rate, thus stabilizing fluctuations in source concentration in the bubble effluent from a computer or similar monitoring device. Such an apparatus and method improves the stoichiometry control of mixed metal oxide film deposition and increases the manufacturability of thin films.

Abstract: A stack gas monitor system has an optimized gas flow portion which is permanently installed in a fossil fuel burning facility, and to which a spectrophotometric portion can be readily coupled for real-time determination in the system of a concentration of a first gas having a characteristic absorption spectrum and which is selectably introducible as a measured amount into a stack gas stream. A sample of the stack gas stream is flowing through the gas flow portion, with at least one gas of the sample stream having an absorption spectrum extending within an ultraviolet range of wavelengths of radiation and having absorbance values within this range which are higher than absorbance values of the first gas. The system can be purged and can be calibrated with the first gas. Stack gas blank data are obtained in the absence of the first gas. Composite gas data are provided upon introduction of the first gas into the stack gas.

Abstract: An atomic absorption spectrometer for measuring mercury concentration in a sample which includes an arrangement for producing emission lines of 184.9 and 253.7 nm at the same time, a sample accommodating chamber which can be irradiated with radiation of the emission lines, two electro-optical transducers responsive, with different sensitivities, to the radiation emission lines and arranged so that radiation passing through the sample chamber simultaneously impinges thereon, each extinction measuring means having a preselected extinction value range, and a comparator for switching between respective measurement ranges to determine the mercury concentration.

Abstract: A light beam is passed through a tube containing a material being monitored and a contaminant wherein the light is absorbed by the contaminant or some form of the contaminant to the exclusion of the material being monitored. Since the amount of light passing through the tube is a function of the amount of contaminant in the tube, the amount of light detected at the downstream end of the tube is a function of the amount of contaminant in the material being monitored. The detected light can be used to provide a quantitative indication of the contaminant, to provide an alarm, to shut down the system to which the material being monitored is being delivered or for other purposes. When the material being monitored is HCl gas and the contaminant is moisture, the tube will generally be stainless steel to avoid galvanic effects since the remainder of the pipe system is generally also stainless steel and the light frequency will be from about 1.0 to about 2.

Abstract: A gas analyzer capable of simultaneously detecting two or more components in a single-cell mode and a gas-analyzing mechanism suitable for simultaneously detecting two or more components in a cross-flow modulation single-cell mode are provided. A gas analyzer unit includes two measuring cells, light sources provided on one end side of each of the measuring cells, gas filter cells with interferential gaseous components hindering a detection of components to be measured enclosed provided on the other end side of each of the measuring cells, beam splitters included in two gas filter cells, first- and fourth and second- and third detectors provided on the side of transmitting position and the side of reflecting position, respectively, of each of the beam splitters and a sampling device connected with a rotary valve.

Abstract: A compact atomic absorption analyzer includes a xenon flashlamp, processing circuits, optics, electronic heating apparatus and a photomultiplier. A sample to be tested is heated using electronic (radio frequency) heating apparatus within the optics to subject the sample to thermal energy sufficient to excite the element of the sample to a level at which it will radiate its characteristic line-emission spectra. A high intensity background light having an ultraviolet component is generated by the xenon flashlamp within the optics and this spectral distribution of this light is received by the photomultiplier. The output of the photomultiplier is processed by the processing electronics, with the results of the test displayed, stored and/or downloaded to an external computer or printer.

Abstract: The photometer of the present invention includes an optical system in which an emission beam generated by pulsed ultra violet radiation from a source is split into a sample beam and a reference interference beam by spectrally selective mirrors arranged in series. These mirrors reflect a beam having a wavelength range corresponding to an absorption wavelength of the gas to be detected onto one solid state detector and to pass a beam to a second spectrally selective mirror where a beam having second range of wave lengths corresponding to an interfering gas is reflected onto a second solid state detector. This second beam serves to measure the interfering gas and also as an imperfect reference channel. In a preferred embodiment the radiation from the source is split prior to entering the sample cell.

Abstract: Apparatus for measuring intensity of UV radiation transmittance through a process fluid including a radiation source, a UV detector and a canopy positioned to extend over a space formed along a distance separating the radiation detector and the radiation source located in the fluid, the canopy having an opening for flow of process fluid into and out of the canopy.

Abstract: The present invention relates to a system for generating the same instantaneous pressure between two tanks filled each with a given medium, the first tank including at least one inlet channel and at least one outlet channel for the given medium, the second tank including at least one outlet channel, and means for opening and for closing said channels. The system according to the invention further includes at least one linking capillary between each tank, intended notably for transmitting instantaneously a pressure variation from the first tank towards the second tank.

Abstract: A laser spectrometer suitable for detecting gas components in a test sample in the ultraviolet range. The measuring laser radiation (2) is sent to a nonlinear crystal (20, 40, 41), which increases the nominal laser frequency to the frequency that corresponds to the absorption wavelength of the measured gas. Tripling of the frequency takes place either after passage of the radiation through a single nonlinear crystal (20), or by mixing a frequency-doubled laser beam with the measuring laser radiation (2) in a common, second nonlinear crystal (41).

Abstract: A spectral analyzer has a high efficiency optical collector having a first concave reflector portion and an opposed second concave reflector portion providing an exit passage therethrough, and a light emitting source of a predetermined wavelength range is positioned in the collector so that the light is collected and directed to the exit passage. A specimen holder is positioned adjacent the exit passage and has windows at its entrance and exit ends. An elongated reverse non-imaging optical member which has a peripheral wall reflecting light rays entering through the exit window of the holder reduces the angle of the rays relative to the optical axis of the optical member as they pass therethrough. The light passing through the exit end of the optical member enters a detector assembly including at least one photo detector sensitive to a predetermined wavelength of light, and at least one optical filter disposed between the optical member and the photodetector to pass light of the predetermined wavelength.

Abstract: An ultra-violet absorbence-based monitor for on-line monitoring of organic pollution in water at on-site locations measure the reduction in UV light passed through a sample and also makes measurements to provide indications of the amounts of visible light absorbed by, and scattered by, the samples respectively. The amount of organic matter is determined from the measured reduction in UV light by a calculation in which the results of the other measurements are used for compensation purposes. The sampling apparatus comprises a buoyant sampling head with an inlet port submerged beneath the water surface.

Abstract: A gas analysis device for the remote detecting, measuring and recording of NO, CO, CO.sub.2, HC, and H.sub.2 O levels from the exhaust (30) of moving motor vehicles (28) utilizes a source (11) of collimated infrared and ultraviolet radiation (15) and includes a detector unit (16) positioned on the opposite side of the roadway for receiving and measuring the infrared and ultraviolet radiation from the source (11) tranmitted through the vehicle exhaust. The detector unit splits the combined infrared and ultraviolet radiation into separate infrared and ultraviolet beams (42) and (40). The ultraviolet beam is diffracted onto a photodiode array in a spectrometer that generates a signal indicative of NO in the vehicle exhaust. A rotating reflector (27) time-multiplexes the infrared beam to a plurality of infrared sensors that generate electrical signals indicative of, for example, CO, CO.sub.2, HC, and H.sub.2 O in the vehicle exhaust. A computer (17) then computes the relative concentrations of CO, CO.sub.

Abstract: An improved sample cell for use in a gas analyzer has a sample body with a measuring optical path extending traverse to the cell body. A sample gas inlet port is positioned at one end of the cell body, and a sample gas outlet port is positioned at the other end of the cell body. Porous plates can extend across the cell body, and appropriately-dimensioned apertures in the porous plates can ensure a consistent flow path of gas across the optical path without any stagnated flow patterns.

Abstract: A method for determining the suitability of a distillate fuel for use after storage by measuring the absorption of ultraviolet light by the fuel.

Abstract: An apparatus that conducts in situ analyses of fluids in real time is disclosed. The apparatus comprises bifurcated optic fibers, a pulsed light source, a light detector, a water-tight pressure case that houses the pulsed light source and the light detector, and a flow-through cell that receives one end of each bifurcated optic fiber. The flow-through cell may comprise a plurality of attached tube sections that define a volume which acts as a passageway for conducting fluids. One or more sections of the flow-through cell may be adapted to introduce a reagent into fluid flowing through the cell. Sections of the cell may contain potassium periodate and N,N-diethylaniline that are released into a fluid flowing through the passageway, enabling the spectrophotometer to analyze manganese (II) concentrations by monitoring the decrease in fluorescence accompanying the oxidation of DEA to 2 DEA'. The fluid may also be analyzed by measuring reflectance, absorption, turbidity, and fluorescence.

Abstract: A method and apparatus for detecting the presence of a predetermined hydrocarbon vapour of a predetermined concentration in a monitored area by: exposing gas in or from the monitored area to radiation from a Xenon flashlamp which includes ultraviolet radiation of a predetermined ultraviolet spectral range and infrared radiation of a predetermined infrared spectral range; detecting the radiation after having passed through the gas; and comparing the detected radiation with a reference of predetermined attenuation characteristics of the hydrocarbon vapour and concentration in the respective ultraviolet and infrared spectral range.

Abstract: The concentration of a water soluble corrosion inhibitor formulation in the water of an aqueous system is monitored by a UV absorption method which is based upon the measurement of the absorbance of a component of corrosion inhibitor formulation. The method is particularly suited to on-site determinations of inhibitor residuals in large aqueous systems, such as in oil field applications, which have an acute need for rapid and adaptable assays, so as to provide precise information before corrosion damage can occur.

Abstract: A calibration method and apparatus for use in measuring the concentrations of components of a fluid is provided. The measurements are determined from the intensity of radiation over a selected range of radiation wavelengths using peak-to-trough calculations. The peak-to-trough calculations are simplified by compensating for radiation absorption by the apparatus. The invention also allows absorption characteristics of an interfering fluid component to be accurately determined and negated thereby facilitating analysis of the fluid.

Abstract: The dual path ultraviolet hygrometer makes use of two narrow spectrum light beams of different wavelengths, both of which are transmitted along two geometrically similar paths to measure and compensate for the presence of contaminants and to more precisely measure the water vapor content in the air samples. A first one of these optical wavelengths is highly absorbed by water vapor while the second optical wavelength is only slightly absorbed by water vapor. Both of these generated narrow band light beams are split so that two pairs of light beams are produced. Beams of both wavelengths are transmitted along the first optical path, which traverses the air sampling chamber. By measuring the differential absorption between the two light beams along this first optical path, the water vapor content of the air sample within the air sampling chamber is precisely measured by correcting for contaminant absorption.

Abstract: A method of making a two-dimensional measurement of the concentration of a biological macromolecule aqueous solution and an apparatus for carrying out this method are disclosed. By charging the biological macromolecule aqueous solution and an aqueous crystallizing agent solution into a crystallizing cell, irradiating the crystallizing cell with an ultraviolet light from an ultraviolet light source, two-dimensionally scanning the ultraviolet light transmitted through the crystallizing cell by a linear image sensor to detect the quantity of the transmitted light, and carrying out a conversion of the detected quantity of the transmitted light to the protein concentration, the process of a crystallization of the biological macromolecule from biological macromolecule aqueous solution can be easily and accurately twodimensionally measured.

Abstract: A furnace with two hot zones holds multiple analysis tubes. Each tube has a separable sample-packing section positioned in the first hot zone and a catalyst-packing section positioned in the second hot zone. A mass flow controller is connected to an inlet of each sample tube, and gas is supplied to the mass flow controller. Oxygen is supplied through a mass flow controller to each tube to either or both of an inlet of the first tube and an intermediate portion between the tube sections to intermingle with and oxidize the entrained gases evolved from the sample. Oxidation of those gases is completed in the catalyst in each second tube section. A thermocouple within a sample reduces furnace temperature when an exothermic condition is sensed within the sample. Oxidized gases flow from outlets of the tubes to individual gas cells. The cells are sequentially aligned with an infrared detector, which senses the composition and quantities of the gas components.

Abstract: An ultraviolet liquid purification system includes a purification chamber having banks of ultraviolet lamps distributed therein for applying germicidal ultraviolet radiation to the liquid flowing through in said chamber. Ultraviolet photocell detectors are located in said chamber to detect the level of ultraviolet radiation transmitted through the quartz jacket housing the ultraviolet lamps and through the liquid being purified. Indicator means produce an alarm signal when the total ultraviolet radiation transmitted through the liquid drops below a preselected level. In addition, a light conducting fiber is provided for each ultraviolet lamp having its input endface located at the ultraviolet lamp and its output endface at a display panel whereby identification of a particular ultraviolet lamp that has failed may be easily detected. Photocell detector means are provided to detect the light output at the output endface of the light conductor fiber and to produce an alarm signal when said light output fails.

Abstract: A gas analyzer arrangement for detecting the presence or quantity of a gas of interest includes a source of electromagnetic radiation for directing a light beam through a light conditioning device such that the light beam is collimated into a parallel beam of light. The conditioned light beam is then directed through a gas sample cell which contains a sample of the gas of interest. The gas of interest has associated therewith, vibrational rotational absorption lines specific to that gas and which are effective for altering the light beam according to the absorption characteristics thereof. The altered light beam is then directed to a birefringent etalon device which has been sized specifically to match those absorption lines of the gas of interest.

Abstract: A spectral analyzer has a high efficiency optical collector having a first concave reflector portion and an opposed second concave reflector portion providing an exit passage therethrough, and a light emitting source of a predetermined wavelength range is positioned in the collector so that the light is collected and directed to the exit passage. A specimen holder is positioned adjacent the exit passage and has windows at its entrance and exit ends. An elongated reverse non-imaging optical member which has a peripheral wall reflecting light rays entering through the exit window of the holder reduces the angle of the rays relative to the optical axis of the optical member as they pass therethrough. The light passing through the exit end of the optical member enters a detector assembly including at least one photo detector sensitive to a predetermined wavelength of light, and at least one optical filter disposed between the optical member and the photodetector to pass light of the predetermined wavelength.