Abstract: The invention relates to a method for determining the particle size distribution of an aerosol by means of an aerosol measuring device and to an aerosol measuring device. Aerosol particles of the aerosol flowing through the measuring cell are illuminated in the measuring cell by a light beam. The scattered light is picked up by a detector, so that light signals of the aerosol particles can be detected spectroscopically in terms of intensity. From this, a size distribution of the light signals that is representative of a particle size distribution is produced. A known standard particle size distribution of dry aerosol particles is adapted to the measured particle size distribution, so that moisture influences are eliminated from the measured particle size distribution in this way.

Abstract: Embodiments of the disclosure are drawn to apparatus and methods for determining gas flux measurements. A gas plume may be emitted from a source and may be blown by wind in an environment. A measurement system, such as a light detection and ranging (lidar) system may collect a plurality of gas concentration measurements associated with the gas plume at a plurality of locations in the environment. A gas flux may be determined based on one or more of the gas concentration measurements along with a wind speed at a location associated with the gas plume. In some embodiments, a height of the gas plume may be determined, and the wind speed at the height of the gas plume may be determined and used to determine the gas flux.

Abstract: Various control systems for controlling a surgical system according to detected airborne particulate characteristics are disclosed.

Abstract: Provided are a system and method of reproducing individual puffs based on empirical data collected by a plurality of electronic vaping devices during use of the vaping devices by users to inhale vapors. The method involves receiving, over a communication network for each of the plurality of electronic vaping devices: (i) reservoir information indicative of a configuration of a reservoir storing a liquid that is at least partially converted into the vapor, and (ii) a plurality of operational parameters for each of a plurality of puffs drawn by the users. The operational parameters include a first operational parameter measured by a sensor system provided to the respective electronic vaping device. An evaluation vaping device is controlled to reproduce a puff by generating a vapor based on the received reservoir information and the received plurality of operational parameters in effect during the puff that is being reproduced.

Abstract: A detection method and detection system for a trace gas, the detection method comprising: providing a resonant cavity, a gas to be measured being filled inside of a cavity body of the resonant cavity; providing detection light rays having different frequencies, the detection light rays being incident to the inside of the resonant cavity from one end of the resonant cavity in the extending direction and exiting from the other end of the resonant cavity in the extending direction so as to obtain detection light rays carrying information of a trace gas to be measured, and the cavity body of the resonant cavity having a degree of freedom of expansion and retraction in the extending direction so that the longitudinal mode frequency of the resonant cavity matches the frequencies of the incident detection light rays; and according to the detection light rays that have different frequencies and that carry information of said trace gas, acquiring the molecular saturation absorption spectrum of said trace gas, and calc

Abstract: A particle concentration measurement system includes a first window and a second window in a housing. The first window and the second window respectively define a first end and a second end of an interaction region between the first window and the second window. The system also includes a particle-laden gas inlet through a wall of the housing between the first window and the second window. The particle-laden gas inlet introduces particle-laden gas from an environment that includes particles mixed with other materials into the interaction region. A first set of clean gas inlets through the wall of the housing are at different radial positions of the housing and at a first axial location of the housing, and a second set of clean gas inlets through the wall of the housing are at different radial positions of the housing and at a second axial location of the housing.

Abstract: An extractive gas analyser system includes a supply channel, a measuring channel connected thereto between first and second ends, an analysing unit comprising an optical arrangement for analysing gaseous material in the measuring channel, which optical arrangement comprises first and second optical units arranged respectively at first and second ends of the measuring channel, a barrier arrangement near each end of the measuring channel and comprising a barrier gas inlet and outlet arranged in opposing manner across said measuring channel, each in connection with a gas source and provided with a nozzle opening directed toward the opposing outlet, said barrier arrangement arranged to provide pressurized gas creating a barrier gas curtain between the barrier gas inlet and outlet to force least a part of the gaseous material from the supply channel into the measuring channel and out through the outlet and thereby separate the gaseous material from said optical units.

Abstract: A first radiance meter is directed toward an object to be measured, radiance is measured through a space where dust is present with the use of at least two wavelengths by the first radiance meter, second radiance meters which are equal in number to one or more objects having temperatures different from that of the object to be measured are directed toward the objects, radiances are measured through the space with the use of at least two wavelengths by the second radiance meters respectively, and a temperature of the object to be measured, a temperature of the dust, and concentration of the dust are measured from the radiances measured by the first radiance meter and the second radiance meters.

Abstract: ABSTRACT OF THE DISCLOSURE An aromatic polyester containing a repeating unit (A) having Formula (a) below; a repeating unit (B) derived from an aromatic dicarboxylic acid, such as terephalic acid; a repeating unit (C) derived from an aromatic amine optionally having a hydroxyl group; and a repeating unit (D) derived from an aromatic diol. The content of (A) is 10 mol % to <20 mol %, the content of (B) is 40 mol % to <45 mol %, the total content of (C) and (D) is 40 mol % to <45 mol %, and the content of (D) is >0 mol % and <15 mol % with respect to a total of (A) to (D). In the Formula (a), Ar1 is a 1,4-phenylene group, a 2,6-naphthylene group, or a 4,4?-biphenylene group; and at least one hydrogen atom in AO may be each substituted with a halogen atom, an alkyl group, or an aryl group.

Abstract: A laser gas analyzer includes: an optical emitter that irradiates laser light onto a measurement target gas; a reflector that reflects the laser light after the laser light passes through the measurement target gas; an optical receiver that receives the reflected laser light; a controller that controls the optical emitter and processes an output signal from the optical receiver; a tubular measurement target gas passage disposed between the optical emitter and the reflector and that includes an opening that allows the measurement target gas to flow into and out of the measurement target gas passage; a first purge region disposed on the optical emitter side of the measurement target gas passage; and a first separation wall that separates the measurement target gas passage and the first purge region and that includes a hole through which the laser light passes.

Abstract: A probe for an IR or UV sensor comprising a light emitter and detector is described comprising a lens. The detector detects the spectrums of the emitted light after it has passed a gas to be measured. The sensor of the present invention is especially suitable for such as harsh or aggressive environments measuring the exhaust gasses, for example in ships, vehicles, chimneys etc., and comprises purge gas protections for delicate optical parts to prevent particles etc. from the exhaust gas depositing on the optics. The sensor further has a flow of sample gas from the gas to be measured being adapted to prevent the purge gas from inferring with the measurements.

Abstract: The gas content of a liquid is quickly and reliably controlled by delivering at least one sub-quantity of the liquid into a measurement cell in which a negative pressure is set. A wave-shaped measurement signal is applied to the sub-quantity, and the wave-shaped measurement signal is measured by at least one detector after coming into contact with the sub-quantity of the liquid. A turbidity value of the liquid is determined and compared with a threshold. If the turbidity value is greater than or equal to the threshold, a pressure and a temperature in the measurement cell are measured, and the gas content in the liquid is ascertained using stored characteristics for the solubility of the gas in the liquid dependent on the pressure and temperature.

Abstract: The invention relates to a tester and test method for smoke amount of electrical cigarette. The tester includes a collect device, a testing device, a control device as well as an input and output device. The input and output device is used to set test parameters, alarm and display a value of smoke amount and a test result whether qualified. The collect device, used to collect smoke, can precisely control a pumping smoke time and a pumping smoke capacity by introducing a step motor. The testing device, utilizing a light emitter and receiver, test a smoke amount. If the smoke amount tested is less than a predetermined smoke amount, an alarm system alarms by way of display and/or sound. The invention quantifies smoke amount of electronic cigarette, which can be adopted in the manufacture field of electronic cigarette to test smoke amount.

Abstract: A gas or particulate sensor is provided for the detection of at least two target gases and/or particulates. The sensor comprises: a chamber for containing a gas sample under test; a first optical measurement channel configured for the detection of a first target gas or particulate within the gas sample, and a second optical measurement channel configured for the detection of a second target gas or particulate within the gas sample, each optical measurement channel comprising a respective optopair which comprises a radiation source adapted to emit radiation and a radiation detector adapted to output a signal in response to detected radiation; and focusing optics able to form an image of an object.

Abstract: In order to be able to prevent analysis accuracy from being reduced by a backward flow of sample gas from dead volume in a cleaning mechanism into a cell at the time of analysis, a gas analysis device has an analysis part that analyzes the sample gas introduced into the cell, gas ports that are arranged toward predetermined regions of gas contact surfaces in the cell, and a piping mechanism that connects the gas ports to a predetermined purge gas source, and blows purge gas from the gas ports toward the predetermined regions at the time of purging. The gas analysis device also has a switching part that switches a connecting destination of the piping mechanism from the purge gas source to a predetermined suction part, and at the time of introducing or analyzing the sample gas, connects the gas ports to the suction source.

Abstract: A method and apparatus for quantitative and qualitative imaging of fugitive emissions of gas, vapors, or fumes are described. The apparatus includes a filter mosaic for placement in registration over an imaging focal plane array (FPA). The filter mosaic includes at least two filter elements providing transmission response functions for transmitting wavelengths of light corresponding to an absorption wavelength (online wavelength) and a non-absorption wavelength (offline wavelength) of the targeted fugitive emission. Also described is an image processing method for transforming a filtered image into an image of the targeted fugitive emission.

Abstract: A method of analyzing a fluid sample from a reservoir comprises: collecting the sample in a sampling container, wherein the sample container includes a sample receptacle, and wherein the step of collecting comprises allowing or causing the sample to flow into the sample receptacle; and determining at least one property of the sample, wherein the step of determining comprises using a multivariate optical element (MOE) calculation device, and wherein the step of determining is performed during the step of collecting and wherein the MOE calculation device is located at one end of the sample receptacle, or the step of determining is performed after the step of collecting. The sample is analyzed as the sample flows into the sample container or as the sample is being transferred from the sample container into a container.

Abstract: A soot number determining device has an intake line for taking in a soot-containing gas through a filter paper that has been introduced into the intake line. A transport apparatus transports a soot spot, which is produced at an intake position by virtue of the gas being taken in on the filter paper, by transporting the filter paper further to an evaluation position. A device is used to determine the extent of blackening of the filter paper.

Abstract: Configurations herein include a novel process, system, etc., to measure a concentration of sulfur trioxide in a gas sample including sulfur trioxide, sulfur dioxide, and water. An example system can include an optical radiation source that generates an optical signal at a plurality of vibration-rotation transitions around at least one frequency selected from the group consisting of 1396.889 cm?1, 1396.908 cm?1, 1396.962 cm?1, 1397.003 cm?1, 1397.037 cm?1, 1397.047 cm?1, and 1397.052 cm?1. The optical signal is transmitted along an optical path through the gas sample. Based on adjusting a pressure of the gas sample, each of the plurality of vibration-rotation absorption transitions associated with the sulfur trioxide can be substantially isolated from interfering absorption by the sulfur dioxide and the water vapor in the gas sample. Based on a spectral analysis, the system generates a value indicative of a concentration of sulfur trioxide in the gas sample.

Abstract: A photoacoustic apparatus obtains information on a specimen by receiving photoacoustic waves which are generated from the specimen resulting from light irradiated to the specimen. The apparatus includes a light source for irradiating light to the specimen, an acoustic wave receiver for receiving the photoacoustic waves, and a light reflection member for causing the light, which is radiated out of the specimen by optical diffusion thereof after having entered an interior of the specimen from the light source, to reenter the interior of the specimen, wherein the light reflection member allows elastic waves to pass therethrough. As a result, a photoacoustic apparatus and a probe are provided which can confine scattered light from the specimen into the specimen, and which can reliably prevent photoacoustic waves from being generated from a receiving element region of the probe by the scattered light.

Abstract: A method and device for measuring trace levels of particles in an air sample is described. A device operating in a gradiometer configuration with two cavities built from a monolithic structure and utilizing a single probe laser, provides common mode subtraction of acoustic, vibrational, laser intensity and other noise sources, which allows sensitivity more closely approaching the quantum limit. Differential measurements between the two cavities occur simultaneously, which reduces errors due to cavity drift. Absorptive gradiometry can therefore provide noise immune detection for trace gasses, including broad linewidth absorbers where frequency-noise immune schemes are not practical. Differential measurements can be used for background subtraction, sensing vapor plum gradients and determining vapor plume propagation direction.

Abstract: A system for and method of mapping process samples which are present in an environmental control chamber at a plurality of “X”-“Y” locations on the surface thereof, wherein the system includes a shield between windows for entering and exiting a beam of electromagnetic radiation, and a process sample.

Abstract: A photoacoustic apparatus obtains information on a specimen by receiving photoacoustic waves which are generated from the specimen resulting from light irradiated to the specimen. The apparatus includes a light source for irradiating light to the specimen, an acoustic wave receiver for receiving the photoacoustic waves, and a light reflection member for causing the light, which is radiated out of the specimen by optical diffusion thereof after having entered an interior of the specimen from the light source, to reenter the interior of the specimen, wherein the light reflection member allows elastic waves to pass therethrough. As a result, a photoacoustic apparatus and a probe are provided which can confine scattered light from the specimen into the specimen, and which can reliably prevent photoacoustic waves from being generated from a receiving element region of the probe by the scattered light.

Abstract: A sensor head for a dry powder agent according to an exemplary aspect of the present disclosure includes a housing defined along an axis along which light is communicated, the housing defines a multiple of apertures transverse to the axis and in communication with a measurement volume along the axis. Each of the multiple of apertures defines a longitudinal length along the axis which is less than a lateral length defined around the axis. A minor is within the housing to reflect the light through the measurement volume.

Abstract: A method and device for measuring trace levels of particles in an air sample is described. A device operating in a gradiometer configuration with two cavities built from a monolithic structure and utilizing a single probe laser, provides common mode subtraction of acoustic, vibrational, laser intensity and other noise sources, which allows sensitivity more closely approaching the quantum limit. Differential measurements between the two cavities occur simultaneously, which reduces errors due to cavity drift. Absorptive gradiometry can therefore provide noise immune detection for trace gasses, including broad linewidth absorbers where frequency-noise immune schemes are not practical. Differential measurements can be used for background subtraction, sensing vapor plume gradients and determining vapor plume propagation direction.

Abstract: Apparatus for performing Raman analysis may include a laser source module, a beam delivery and signal collection module, a spectrum analysis module, and a digital signal processing module. The laser source module delivers a laser beam to the beam delivery and signal collection module. The beam delivery and signal collection module delivers the laser source beam to a sample, collects Raman scattered light scattered from the sample, and delivers the collected Raman scattered light to the spectrum analysis module. The spectrum analysis module demultiplexes the Raman scattered light into discrete Raman bands of interest, detects the presence of signal energy in each of the Raman bands, and produces a digital signal that is representative of the signal energy present in each of the Raman bands. The digital signal processing module is adapted to perform a Raman analysis of the sample.

Abstract: A particle monitoring apparatus includes a housing disposed on a gas exhaust line, a laser beam source for emitting a laser beam to particles in the gas exhaust line, a window member disposed at the housing for monitoring the particles in the gas exhaust line. The window member has a transparent base which is formed of a transparent resin or glass containing silicon and has a gas contact surface which faces a gas within the gas exhaust line, and a surface treatment layer formed on the gas contact surface of the transparent base, wherein the surface treatment layer contains one material selected from the group consisting of yttrium and calcium fluoride.

Abstract: An apparatus and method for estimating size segregated aerosol mass concentration in real time and using a single detector. A beam of electromagnetic radiation is passed through a particle stream made of a test or field aerosol. The single detector outputs an electrical signal proportional to the electromagnetic radiation scattered thereupon. The electrical signal may be conditioned to produce an integrated signal for measuring radiation scattered from all the particles in the interrogation volume, a pulse height from an individual particle within the volume, and/or a time-of-flight measurement from the individual particle. The integrated signal can be correlated to particle mass concentration. The pulse height signal and the time-of-flight signal may be converted to infer the size of the individual particle. Attendant size distributions for the particle sizes may also be obtained. Using known or assumed particle properties, the mass concentration may be estimated from the size distribution.

Abstract: This invention can suppress adhesion of dust to the surface of an optical filter and the cover glass surface of a solid-state image sensor without any optically adverse effect. An image capturing apparatus includes an image capturing device which converts the optical image of an object into an electrical signal, and an optical element (11) arranged in front of the image capturing device. Minute particles of a single layer (11a) are arrayed on a surface of the optical element on the object side.

Abstract: There is described a method for measuring a concentration of a gas component in a measuring gas, wherein the light of a wavelength tunable light source is passed along a single optical path through a measuring volume containing the measuring gas and a reference cell containing a reference gas to a detector. The reference cell is selected to contain a selected isotope of the gas component to be measured in a known abundance ratio higher than the known natural-abundance isotope ratio of the gas component in the measuring volume; the light source is tuned to sweep the wavelength of the light over the absorption lines of the selected isotope and the remaining gas component; and the concentration of the gas component in the measuring volume is calculated from the ratio of the detector signals at the peaks of the absorption lines, based on Lambert's law and taking into account the known abundance isotope ratios.

Abstract: A particle detection device and method wherein a bulk sample of particles is selectively collected based on scattering properties of the particles and fluorescence properties of the particles. The bulk sample of particles is then excited to produce an atomic emission from the bulk sample of particles. The atomic emission from the bulk sample of particles is used to determine atomic emission properties of the particles and identify biological particles in the bulk sample.

Abstract: A sensor head for a dry powder agent according to an exemplary aspect of the present disclosure includes a housing defined along an axis along which light is communicated, the housing defines a multiple of apertures transverse to the axis and in communication with a measurement volume along the axis. Each of the multiple of apertures defines a longitudinal length along the axis which is less than a lateral length defined around the axis. A minor is within the housing to reflect the light through the measurement volume.

Abstract: A system for providing photoacoustic spectroscopy. A light source having a quantum dot filter may provide a band of infrared light which is to be reflected by a lamellar grating to a photoacoustic chamber. The light may be modulated by the grating. The chamber may contain a sample of fluid for which spectral information is sought. A sensor may detect acoustic pressures in the chamber which indicate the spectral information. Signals from the sensor may be processed and displayed. Identification and concentration of certain substances in the fluid may be obtained.

Abstract: A testing device equipped with: a microchip having a receiver for a test fluid, a discharge lamp which emits light into the microchip test fluid receiver, a light source housing in which the discharge lamp is located, and an arithmetic calculation mechanism, which calculates the concentration of the component to be detected, based on the intensity of the light emitted from the test fluid container unit. To reduce the size of the device and to shield the arithmetic calculation mechanism from electromagnetic waves generated around the light source, the light source housing is equipped with shielding connected to the ground on the outside of the light source housing made of insulating material. The light source housing is positioned within an enclosure of the testing device holding the microchip and containing the arithmetic calculation mechanism, analysis output device(s), and other components of the testing device.

Abstract: A method for measuring combustion parameters within a combustion zone of a gas turbine engine, the combustion zone being defined between an inner and outer casing. The method comprises transmitting a beam from a transmit optic optically coupled to a bore in the outer casing off a portion of the inner casing and receiving a portion of the beam reflected off the inner casing with a receiving optic optically coupled to a bore in the outer casing. An apparatus for practicing the method comprises a laser generating a beam and a transmitting/receiving optics pair, the transmitting/receiving optics pair being configured for operative association with a port in an outer casing of a gas turbine engine, whereby the transmitting/receiving optics are in optical communication by reflecting the beam off a portion of an inner casing.

Abstract: A chemical reactor includes two substrates that are joined along a surface and a chemical reaction chamber formed between the substrates. The chemical reaction chamber has a hollow interior and one or more light reflectors located along walls of the hollow interior. The chemical reaction chamber has one or more inputs to transport fluid into the hollow interior and an output to transport fluid out of the hollow interior. The one or more light reflectors cause light rays to make multiple crossings of the hollow interior as a result of reflections off the one or more reflectors.

Abstract: A meter for measuring the turbidity of a fluid includes a light source for directing a light beam through a fluid under test towards a reflective surface and a sensor for detecting light reflected from the reflective surface and passing back through the fluid under test. The meter outputs a signal indicative of the turbidity of the fluid under test.

Abstract: A spectroscopic gas sensor is provided, in particular to detect at least one gas component in the ambient air, and a method for the manufacture of a spectroscopic gas sensor of this type. The gas sensor includes the following: at least one radiation detection device for detecting a radiation spectrum that is characteristic for the at least one gas component; a package for receiving the at least one radiation detection device, having at least one package wall end section; and at least one optical component having at least one connecting section that is connectable to the at least one package wall end section by hot-caulking the at least one package wall end section.

Abstract: An improved elemental mercury analyzer utilizes a fluorescence assembly in combination with a fluorescence quenching reduction mechanism to detect the concentration of elemental mercury within an emission gas sample, via fluorescence of the mercury within the gas sample, while minimizing fluorescence quenching of the gas sample. In one arrangement, the analyzer contains the emission gas sample under a vacuum or negative pressure while detecting fluorescence of the elemental mercury within the emission gas sample. By performing fluorescence detection of the emission gas sample at reduced pressure relative to the pressure of the as-sampled emission gas, the analyzer reduces the number of particle collisions within the emission gas sample over a certain period of time. Such collisional deactivation, and/or the addition of oxygen depleted gas such as nitrogen to the gas sample, reduces fluorescence quenching of the emission gas sample, improving accuracy of detection of mercury.

Abstract: An apparatus and method for monitoring oxygen concentrations in fuel tank ullage comprising providing a sensor head comprising an optical cavity, exposing the optical cavity to an ambient gaseous environment of a fuel tank or air separation module, via a laser light source emitting wavelength modulated light through the cavity, and receiving the wavelength modulated light with a detector.

Abstract: A method apparatus for sensing gases using a semiconductor diode laser spectrometer, the method comprising: introducing a sample gas into a non-resonant optical cell (17); applying a step function electrical pulse (19) to a semiconductor diode laser (20) to cause the laser (20) to output a continuous wavelength chirp for injecting (16a) into the optical cell (17); injecting (16a) the wavelength chirp into the optical cell (17); using the wavelength variation provided by the wavelength chirp as a wavelength scan, and detecting (23) light emitted from the cell (17), wherein a chirp rate is selected to substantially prevent light interference occurring in the optical cell (17).

Abstract: This invention relates to a multi-component absorbance monitor, and the object is to provide a general-purpose and highly accurate compact absorbance monitor. Disclosed is an absorbance monitor including a light source, a sample cell and a plurality of detectors as elements, wherein a light collecting member is arranged between the light source and one detector, and an inside wall of the light collecting member has a site for guiding a part of light from the light source, that is, a light guiding opening, and light from the light guiding opening enters another detector. Preferably, the light collecting member lies between the light source and the sample cell. Preferably, an optical element used for another detector described above is arranged in the light guiding opening and adjacently to a light path formed by the light collecting member.

Abstract: A lightweight and portable analyzer is provided. At least one component of the analyzer is made from a lightweight material, such as ABS. A manifold can have a plate and gas passages ultrasonically welded together. By having at least one component made from a lightweight material, the analyzer is lighter.

Abstract: An ethanol sensing unit and a method of using, wherein the unit is particularly suitable for use in a confined environment such as the passenger compartment of a passenger vehicle. The sensing unit comprises a device for collecting ethanol vapors while the device is at a first temperature, a device for heating the collecting device to a second temperature higher than the first temperature so as to release ethanol vapors from the collecting device, and a device for sensing the ethanol vapors released from the collecting device when heated by the heating device. The sensing unit is also adapted to delay the operation of the heating device until a period of time sufficient for the collecting device to adsorb ethanol vapors from air contained in the confined environment.

Abstract: An infrared absorption measurement method includes: (a) measuring infrared absorption of a measurement target component in a state in which a sample gas including the measurement target component is decompressed; (b) calculating an absorption area in a peak region of the measurement target component in the infrared absorption shown in a graph which shows the relationship between the wave number and absorbance of the sample gas; and (c) calculating a concentration of the measurement target component in the sample gas based on the absorption area and pressure of the sample gas during decompression.

Abstract: Purging of a light beam path in an effective manner that minimizes the affect of the purging requirement on system throughput. In one embodiment, the invention is incorporated into a birefringence measurement system that has several components for directing light through a sample optical element and thereafter detecting and analyzing the light. The segment of the beam path through the sample is isolated to reduce the volume that requires continual purging.

Abstract: A robust gas sensor can be manufactured in a simple manner and at low cost, and have no movable optical components. A measured gas cell (3) has a wall defining a cylindrical space with a measured gas inlet. The measured gas cell (3) is limited in the longitudinal axial direction by a reflective, flat first cover element (1) and by a reflective, flat second cover element (5) arranged at a spaced location from and in parallel to the first cover element (1). The height of the measured gas cell (3) corresponds approximately to 1 to 3 times the diameter of the cover elements (1, 5). The second cover element (5) accommodates a radiation source (6) and two detector elements (23, 24) with at least one measuring detector and one reference detector. The radiation source (6) is arranged displaced by 30% to 60% of the radius of the second cover element (5) from the center of the second cover element (5).

Abstract: A method for conducting laser absorption measurements in high temperature process streams having high levels of particulate matter is disclosed. An impinger is positioned substantially parallel to a laser beam propagation path and at upstream position relative to the laser beam. Beam shielding pipes shield the beam from the surrounding environment. Measurement is conducted only in the gap between the two shielding pipes where the beam propagates through the process gas. The impinger facilitates reduced particle presence in the measurement beam, resulting in improved SNR (signal-to-noise) and improved sensitivity and dynamic range of the measurement.

Abstract: A gas permeable probe for use in an optical analyzer for an exhaust gas stream flowing through a duct or chimney has: an elongate hollow structure having first and second ends and a side wall, with an optical cavity defined between the first and second ends within the side wall, a filter forming part of the elongate hollow structure, a mounting structure at the first end and adapted for mounting the elongate hollow structure within the duct or chimney, an optical window at the first end permitting a light beam originating from an optical analyzer to enter into the optical cavity to travel from the first end to the second end, a retroreflector provided at the second end for returning the light beam to the first end of the hollow structure, and a tube disposed within the mounting structure and having first and second opposite ends, the first opposite end being located remote from the first end of the elongate hollow structure and being closed by a first window adapted to transmit the light beam from an optic

Abstract: A gas permeable probe for use in an optical analyzer for an exhaust gas stream flowing through a duct or chimney has: an elongate hollow structure having first and second ends and a side wall, with an optical cavity defined between the first and second ends within the side wall, a mounting structure at the first end and adapted for mounting the elongate hollow structure within the duct or chimney, a support member at the second end, a connecting structure connecting the mounting structure at the first end to the support member at the second end, an optical window at the first end permitting a beam of light originating from an optical analyzer to enter into the optical cavity to travel from the first end to the second end, a filter forming a part of the side wall, and a retroreflector provided at the second end for returning the light beam to the first end of the hollow structure, the optical window being releasably mounted at the first end of the elongate hollow structure and/or the retroreflector bei