Abstract: A system of sampling a fluid comprises a fluid separator having a central axis. The fluid separator includes an insulating sleeve. In addition the fluid separator includes a separator assembly coaxially disposed within the sleeve. Further, the fluid separator includes an annulus radially disposed between the sleeve and the separator assembly. The separator assembly includes a conduit, a support rod coaxially disposed within the conduit, and a plurality of separator members coupled to the support rod within the conduit.

Abstract: An embodiment of the present invention measures a sample of the airstream, in real time, for a corrosive, before the airstream enters the compressor. An embodiment of the present invention may then initiate an on-line water wash system to reduce the level of the at least one corrosive on the compressor. An embodiment of the present invention also provides an on-line water wash system that may mix a cleaning fluid with at least one chemical agent to form a cleaning solution. The cleaning solution reduces the level of corrosives on components of a turbomachine compressor. The cleaning solution may be an acidic solution to reduce corrosion of a caustic nature. Alternatively, the cleaning solution may be a basic solution to reduce corrosion of an acidic nature.

Abstract: A device and process for separating liquid and gas phases in a flowstream containing a liquefied gas or supercritical fluid under pressure mixed with a liquid. A splitter vessel separates the liquid from gas phases and transfers liquid to a collection container while conducting the gas phase out of the splitter. Separation of liquid phase out of the flowstream is provided without additional pressure schemes or solvent extractions imposed on the stream.

Abstract: A process and sensor device are disclosed that employ metal ?-diketonate polymers to selectively capture gas-phase explosives and weaponized chemical agents in a sampling area or volume. The metal ?-diketonate polymers can be applied to surfaces in various analytical formats for detection of: improvised explosive devices, unexploded ordinance, munitions hidden in cargo holds, explosives, and chemical weapons in public areas.

Abstract: An apparatus for collecting airborne particles includes a cyclone into which external air and an absorbing liquid are sprayed to absorb the airborne particles in the external air with the absorbing liquid, a reservoir in fluid communication with the cyclone and which stores the absorbing liquid to be sprayed into the cyclone as an absorbing liquid film, a collector in fluid communication with the cyclone and which collects the absorbing liquid film from the cyclone, and a feedback pipe in fluid communication with the collector and the reservoir and which transports the absorbing liquid film collected in the collector to the reservoir.

Abstract: A process and sensor device are disclosed that employ metal ?-diketonate polymers to selectively capture gas-phase explosives and weaponized chemical agents in a sampling area or volume. The metal ?-diketonate polymers can be applied to surfaces in various analytical formats for detection of: improvised explosive devices, unexploded ordinance, munitions hidden in cargo holds, explosives, and chemical weapons in public areas.

Abstract: Embodiments of the invention generally provide an apparatus and method for decontaminating tubing. The invention is particularly suitable for decontaminating tubing in a test system used for certifying a filter in a containment system. In one embodiment, a test system for a containment system is provide that includes a sample system including equipment adapted for testing a filter disposed in a containment system utilizing samples obtained from a downstream sample port and a upstream sample port of the containment system, and a device for reversing a flow within the sample system. In another aspect of the invention, a method for decontaminating tubing is provided. In another embodiment, the method includes flowing a sterilization agent through tubing in a first direction and flowing the sterilization agent through tubing in a second direction.

Abstract: A ductless fume hood suitable for the removal of various chemical materials including toxic and non-toxic gases, vapors, particles, dust and unpleasant odors from a fluid stream. The ductless fume hood uses electronic devices and software to enable real time monitoring of gas levels in parts per million.

Abstract: The invention relates to a device for preparing a gas flow for introduction thereof into a mass spectrometer, wherein the gas flow contains one or more analytes and has helium as carrier gas. According to the invention, a selective separating device is provided for separating off a part of the carrier gas from the gas flow (10), to form a residual gas flow (11) and a separated carrier gas flow (12). A higher fraction of the analyte is present therein than in the gas flow and in the separated carrier gas flow there is a lower fraction of the analyte.

Abstract: A gas sample cylinder outlet valve having a flow restricting element associated therewith. The preferred embodiment of the flow restricting element comprises an orifice constructed of a low thermal conduction material such as a plastic. Preferably the outlet valve Cv characteristic is large relative to the orifice Cv characteristic resulting in essentially all of the gas pressure drop taking place across said orifice and therefore essentially all of the J-T effect cooling taking place at said orifice. Due to the low thermal conductivity construction of said orifice an insignificant amount of cooling takes place upstream of the valve mechanism. Test have shown that the integral orifice outlet valve having a large Cv characteristic is more efficient then the typical sample cylinder outlet valve and extension tube and/or flow restrictor combination.

Abstract: A differential absorption spectrum for a reactive gas in a gas mixture can be generated for sample absorption data by subtracting background absorption data set from the sample absorption data. The background absorption data can be characteristic of absorption characteristics of the background composition in a laser light scan range that includes a target wavelength. The differential absorption spectrum can be converted to a measured concentration of the reactive gas using calibration data. A determination can be made whether the background composition has substantially changed relative to the background absorption data, and new background absorption data can be used if the background composition has substantially changed. Related systems, apparatus, methods, and/or articles are also described.

Abstract: A liquid separator for a respiratory gas sample analyzer includes a closed container having a liquid trap filter chamber integral with the container. The liquid trap filter chamber includes an inlet compartment and an outlet compartment. The inlet compartment is interposed between a sample inlet port and a sample outlet port and includes a gas permeable, liquid impermeable filter element for separating liquid from a gas sample, the liquid separated from the gas sample passing to a collection chamber. The outlet compartment includes a further gas permeable, liquid impermeable trap filter element which is interposed between the collection chamber and a low pressure port, for preventing the flow of liquid through the output compartment to the low pressure port.

Abstract: Fan blades within a fan assembly are rotated in a first rotational direction, thereby generating airflow from above the fan blades downward past the fan blades. Airborne particles adhere to the surface of the fan blades as the air flows past. The fan direction is then reversed maintained at a relatively low rotational rate. A fluid is dispensed onto the hub of the fan blades. Due to the centripetal force of the spinning fan blades, the fluid is spread thin across the top surface of the fan blades and the liquid film washes the blade of the fan, removing particulates from the fan blade. The solution is pushed outward against the inner wall of the fan housing forming a fluid meniscus. The fan speed is increased to push the fluid meniscus into an annular reservoir. The collected fluid is then vacuumed and consolidated into the collection vessel.

Abstract: The present invention relates to a gas filtering-buffering device, which comprises at least one gas filtering unit; a gas inlet, the gas to be processed flows into the at least one gas filtering unit from the gas inlet; and a gas outlet, the gas processed by the at least one gas filtering unit is discharged out of the at least one gas filtering unit via the gas outlet, wherein the at least one gas filtering unit comprising: a gas buffering cavity for performing buffering function for the gas, and a gas filtering part for performing filtering function for the gas. In the present invention, it is not only provided with a gas filtering part which is able to filter the moisture and organic substance in the gas, but also provided with a gas buffering cavity, which integrate the filtering and buffering functions together.

Abstract: A particle collector comprises a housing defining an enclosed chamber. An inlet opening in the housing provides fluid communication between a source of gas and particles and the chamber and an outlet opening provides fluid communication between the chamber and the exterior of the housing. The outlet opening is connected to a pump for drawing gas and particles through the housing from the inlet opening to the outlet opening. A collecting member having an adhesive on at least a portion of the surface is disposed in the chamber between the inlet opening and the outlet opening. The adhesive surface of the collecting member is positioned adjacent to the inlet opening. When gas and particles are drawn through the housing, the inlet opening directs a stream of gas and particles at the surface of the collecting member. Particles having an aerodynamic equivalent diameter of less than about 2.5 ?m are captured.

Abstract: A device for sampling of a mixture of ultrafine particles within a moving gas stream includes a suction generator, at least one sample collection element, and a conduit structure coupling the sample collection element with the suction generator. In some embodiments, the suction generator is configurable to separate by suction a portion of a gas stream containing a plurality of ultrafine particles, and to entrain with a motive fluid forming an output mixture. In some embodiments, a conduit is configured to accept a gas stream containing ultrafine particles and to channel it to the collection element.

Abstract: Device for recovering a material to be measured comprising a reservoir filled with a sample holding material impregnated with a sample liquid in which a material to be measured is dissolved and an adsorbing column for adsorbing the material to be measured, wherein the reservoir and the adsorbing column are communicated by a straight pipe, and further communicated with a recovery vessel via a recovery pipe branched out the straight pipe. Accordingly, operations of opening/closing or switching a first valve provided on the in-flow side of the reservoir, a second valve provided on the out-flow side of the adsorbing column, and a third valve provided to a vent hole to the atmosphere in the recovery vessel, make it possible to recover the material to be measured without depositing the material on the valves.

Abstract: A differential absorption spectrum for a reactive gas in a gas mixture can be generated for sample absorption data by subtracting background absorption data set from the sample absorption data. The background absorption data can be characteristic of absorption characteristics of the background composition in a laser light scan range that includes a target wavelength. The differential absorption spectrum can be converted to a measured concentration of the reactive gas using calibration data. A determination can be made whether the background composition has substantially changed relative to the background absorption data, and new background absorption data can be used if the background composition has substantially changed. Related systems, apparatus, methods, and/or articles are also described.

Abstract: A modified liquid impingement unit is configured to automatically maintain a volume of buffer solution within a determined range, the buffer solution used to collect airborne particles from an impinging airflow. The liquid impingement unit includes a first end of an air nozzle and a first end of a vacuum tube sealed within collection vessel. A fluid delivery tube is positioned within the vacuum tube such that a first end of the fluid delivery tube is also positioned within the sealed collection vessel. External to the sealed collection vessel, the fluid delivery tube branches from the vacuum tube through an aperture in the vacuum tube. The vacuum tube is coupled to a vacuum pump and the fluid delivery tube is coupled to a fluid pump. A control module provides control signals to the fluid pump such that the fluid pump delivers a second volume of buffer solution from a buffer solution container to the collection vessel via the fluid delivery tube.

Abstract: A process and sensor device are disclosed that employ metal ?-diketonate polymers to selectively capture gas-phase explosives and weaponized chemical agents in a sampling area or volume. The metal ?-diketonate polymers can be applied to surfaces in various analytical formats for detection of: improvised explosive devices, unexploded ordinance, munitions hidden in cargo holds, explosives, and chemical weapons in public areas.

Abstract: A filter arrangement for removing impurities from a fluid is disclosed, the filter arrangement (10) includes a plurality of screen portions (18, 20) through which the fluid passes. The screen portions include a first screen portion (18) and a second screen portion (20) separated by a predetermined distance. The predetermined distance can be determined on the basis of a threshold particle length. In one form the filter arrangement (10) is mounted in a housing (16) which is configured to receive two filter elements (18, 20) arranged in a nested configuration. A particle detector using the filter is described.

Abstract: A test fixture for collecting particulate matter carried in the exhaust gas stream of an engine has a pair of coaxially aligned mounting plates, each having a filter cartridge holder mounted thereon. One of the mounting plates is moveable with respect to the other along a predefined longitudinal axis of the test fixture between an open position, whereat a filter cartridge is easily placed or removed, and a closed position at which a filter media mounted in the filter cartridge is sealed during a prescribed test sequence. An actuator mounted on a third coaxially aligned mounting plate has an extendable rod connected to the second mounting plate to effect movement of the second mounting plate between the open an closed positions.

Abstract: An embodiment of the present invention measures a sample of the airstream, in real time, for at least one corrosive, before the airstream enters the compressor. An embodiment of the present invention may then initiate an on-line water wash system to reduce the level of the at least one corrosive on the compressor. An embodiment of the present invention also provides an on-line water wash system that may mix a cleaning fluid with at least one chemical agent to form a cleaning solution. The cleaning solution reduces the corrosives on components of a turbomachine compressor. The cleaning solution may be an acidic solution to reduce corrosion of a caustic nature. Alternatively, the cleaning solution may be a basic solution to reduce corrosion of an acidic nature.

Abstract: Various embodiments of the present disclosure provide an inertial separation device, system, and method. The inertial separation device includes an inlet nozzle coupled to an expansion chamber. A sample outlet and an outlet port are coupled to the expansion chamber. In operation, a fluid sample passes though the inlet nozzle and is expanded in the expansion chamber such that the sample is separated into at least two fractions having different masses, a selected mass fraction passing through the sample outlet and a remaining portion of the sample passing out of the outlet port. A system including the inertial separation device includes a conduit coupled to the sample outlet nozzle and a detector coupled the conduit. The inlet nozzle may be, for example, coupled to an emissions source.

Abstract: A soil sampler includes a fluidized bed for receiving a soil sample. The fluidized bed may be in communication with a vacuum for drawing air through the fluidized bed and suspending particulate matter of the soil sample in the air. In a method of sampling, the air may be drawn across a filter, separating the particulate matter. Optionally, a baffle or a cyclone may be included within the fluidized bed for disentrainment, or dedusting, so only the finest particulate matter, including asbestos, will be trapped on the filter. The filter may be removable, and may be tested to determine the content of asbestos and other hazardous particulate matter in the soil sample.

Abstract: Embodiments of the invention generally provide a filter module having a mechanically positionable test probe disposed therein and a method for testing a filter. In one embodiment, a filter module includes a housing adapted to receive a filter element. A sample probe suitable for leak testing the filter element is disposed in the interior volume of the housing. The sample probe may be moved to scan the filter by an actuator. In another embodiment, a method for testing a filter includes challenging a room side of a filter element disposed in a housing with a test aerosol, moving a probe disposed within the housing to obtain samples for testing and determining if the samples exceed a predefined leak criteria.

Abstract: A planar omni-directional inlet assembly is provided for installing on a device, such as a dry filter unit, that draws a fluid medium, such as ambient air, to collect particulate matter suspended in the fluid medium onto a filter. The inlet assembly includes an annular platform removably positionable on the device; an annular nozzle to direct the air from the platform; an annular impactor disposed downstream of the nozzle; a housing that disposes the filter downstream of the impactor; and an exit for passing the air from the filter to the device. The impactor presents a flow obstacle for a portion of the particulate matter. The housing directs the air through the filter. The housing includes a base with a first cavity and a lid with a second cavity such that the filter is disposable between the first and second cavities.

Abstract: A filter assembly for use in sidestream gas sampling assembly. The filter assembly of the present invention includes a hydrophilic member that is constructed from a porous material and is situated such that gas entering the filter assembly passes through at least a portion the hydrophilic member. In a further embodiment, the filter includes a hydrophobic member positioned downstream of the hydrophilic member. The hydrophobic member acts as a second line of defense against moisture reaching the sensing mechanism in the gas sampling assembly.

Abstract: A uniform aerosol deposit sampling device includes a first housing and a second housing. The first housing has an air inlet and a first chamber. The second housing has an air outlet, an second chamber, a filter holder and a flow guiding portion. The filter holder is provided for securing an air-penetratable supporting pad and a filter media. The flow guiding portion is a substantially conical and gradually narrowing. The flow guiding portion has a semi-conical angle ranged from 15 to 85 degrees. So, the flow guiding portion makes the entire air flow smooth and evenly distributed. The aerosols will be evenly distributed and uniformly deposited on the filter media. And, it is easy to evaluate the amount and composition of the aerosols.

Abstract: A filtering system for monitoring fluid emissions from a process includes a plurality of filter assembly sections arranged in a parallel fluid flow manner with respect to each other so as to selectively receive a sample fluid (e.g., a sample gas) entering at an inlet of the system. Each filter assembly section includes a filter unit to filter particulate materials from a fluid flowing through the filter, first and second valves disposed at upstream and downstream locations of the filter unit, and a blowback flow path configured to selectively direct a cleaning fluid through the filter unit in a direction that opposes a direction in which the sample fluid flows through the filter unit. Each filter assembly section can be selectively isolated from other portions of the system so as to prevent the sample fluid from flowing through the filter assembly section while allowing a cleaning fluid to be delivered through the blowback flow path of the filter assembly section.

Abstract: A passive air sampler or badge suitable for wearing includes a vial adaptor to facilitate transferring granular or particulate adsorbent to and from it directly into a specially designed vial sized to accommodate a standard amount for use in a desorption tube for chromatographic or other analysis of the materials desorbed.

Abstract: A filter includes at least two different adsorptive media. First, chemisorptive media, which is porous and includes an acidic functional group, is used to remove molecular bases, including ammonia, organic amines, imides and aminoalchols, from the atmosphere used in semiconductor fabrication and other processes that require uncontaminated gaseous environments of high quality. Second, physisorptive media is able to adsorb condensable contaminants, particularly those having a boiling point greater than 150 degrees C. The physisorptive media can include untreated, activated carbon.

Abstract: Improved apparatus for collecting particles from air comprises a cyclone having air inlet and outlet means, means maintaining an airflow there through and means delivering a collecting fluid from a reservoir to particles separated from the air flow in the cyclone, in which the air inlet means is associated with means for heating the incoming air. The apparatus, which is optionally provided with enclosure means for trapping heat, prevents freezing of the collecting fluid at temperatures near to and even below 0° C.

Abstract: A sampling system includes a collection module including a gas handler, and a flow controller in communication with the gas handler of the collection module. The flow controller controls the gas handler to move a selected volume of gas through the collection module.

Abstract: Embodiments of the invention generally provide an apparatus and method for certifying a filter in a containment system without decontaminating the containment system prior to certification. The apparatus generally comprises a valve assembly selectable between at least three operational states. A first state prevents flow from prevents flow through a port of a housing. A second state fluidly couples the port to test equipment necessary to test a filter disposed within the housing. A third state seals the port but fluidly couples the test equipment to a decontamination system.

Abstract: A device for collecting particles and microorganisms present in ambient air, the device comprising means for sucking air into a small volume enclosure in which the particles and microorganisms are separated from the sucked-in air by centrifuging, the device being portable, self-contained, and capable of being handled in one hand only, e.g. by means of a handle associated with the air suction means.

Abstract: An apparatus for concentrating a vaporous substance, which comprises: a sorbent material capable of capturing a vaporous substance; a first housing in which the sorbent material is located, a heating element proximate the exterior of the housing; a second housing defining a chamber within which the first housing resides, the first housing being located in said chamber such that there is a space permitting gas flow between the outside of the first housing and the inside of the second housing; and a pump capable of causing an exhaust gas to flow through the space in contact with the outside of the first housing; and methods for making and utilizing such apparatus.

Abstract: The invention relates to a dialysis method of recovering foreign substances, particularly low-molecular weight inorganic and/or organic substances, from semipermeable membrane of varying length and dimensions, using a PLE (pressurized liquid extraction) apparatus. The membranes are preferably in the form of a tube, for example semipermeable membrane devices (SPMDs) which, in the form of passive samplers, accumulate foreign substances/pollutants on an absorbent or adsorbent.

Abstract: A soil sampler includes a fluidized bed for receiving a soil sample. The fluidized bed may be in communication with a vacuum for drawing air through the fluidized bed and suspending particulate matter of the soil sample in the air. In a method of sampling, the air may be drawn across a filter, separating the particulate matter. Optionally, a baffle or a cyclone may be included within the fluidized bed for disentrainment, or dedusting, so only the finest particulate matter, including asbestos, will be trapped on the filter. The filter may be removable, and may be tested to determine the content of asbestos and other hazardous particulate matter in the soil sample.

Abstract: A particle collector comprises a housing defining an enclosed chamber. An inlet opening in the housing provides fluid communication between a source of gas and particles and the chamber and an outlet opening provides fluid communication between the chamber and the exterior of the housing. The outlet opening is connected to a pump for drawing gas and particles through the housing from the inlet opening to the outlet opening. A collecting member having an adhesive on at least a portion of the surface is disposed in the chamber between the inlet opening and the outlet opening. The adhesive surface of the collecting member is positioned adjacent to the inlet opening. When gas and particles are drawn through the housing, the inlet opening directs a stream of gas and particles at the surface of the collecting member. Particles having an aerodynamic equivalent diameter of less than about 2.5 ?m are captured.

Abstract: A system is disclosed for condensation particle counting in conjunction with modifying an aerosol to enhance the formation and growth of droplets of a selected working fluid, preferably water. Before saturation with the working fluid, the aerosol is exposed to an aerosol modifying component, preferably a vapor including molecules that are adsorbed onto surfaces of the particles or other elements suspended in the aerosol. Adsorption alters the surface character of the suspended elements towards increased affinity for the vapor of the working fluid, to promote the formation and growth of working fluid droplets. The droplets are optically detected to indicate numbers and concentrations of the suspended elements.

Abstract: An autonomously-cleaned conditioning system conducts a routine purge cycle to clear accumulated particulates from a filter, concentrator, or both. The purge cycle is conducted by reversing air flow through the filter and/or concentrator. Air flow is reversed on a periodic basis or on the occurrence of a condition, such as a reduction in air flow exiting the concentrator.

Abstract: A particle separation apparatus is disclosed. The particle separation apparatus may be for sample air stream preparation and delivery in particle detection systems. The particle separation apparatus may include a first vortex separator coupled to a second vortex separator for selecting particles in the air stream that are within a desirable size range for particle detection. The second vortex separator may further increase the concentration of particles within the desirable size range per unit volume. The particle separation apparatus may deliver the size-selected air stream to a detector, such as a laser-induced fluorescence detection system.

Abstract: A cyclonic separator and methods of cyclonic separation which provide for a band pass separation of particles. That is, a cyclonic separator able to remove particles from an air stream that are greater than a predetermined minimum (which is greater than zero) while being smaller than a particular maximum. This band pass separation may be performed with the inclusion of a secondary vortex break on a cyclonic separator. Also discussed are cyclonic flow systems which provide for less deposition of aerosolized particles onto the cyclonic flow generator and related structures to improve likelihood of particles of interest being provided to an attached detector.

Abstract: Particle collection, transport, and detection systems are disclosed. The systems are uniquely adapted for collecting or concentrating particles from a flowing medium and then transporting the collected particles to a desired location or for subsequent analysis. Electrostatic traveling wave grids can be used in conjunction with sample concentrators.

Abstract: A contamination control apparatus includes at least two pipes connected by a joint portion and configured to allow a processing fluid to flow therethrough, and a cover configured to enclose the joint portion and to provide an enclosed cavity between the cover and the joint portion. An inlet port is connected to the cover and configured to supply a gas to the cavity. An outlet port is connected to the cover and configured to exhaust the gas and a contaminant from the cavity.

Abstract: The invention provides a system and method comprising an apparatus for removing contaminants from a gas in a semiconductor processing device, which can include a filter unit having at least two parallel filter stages located therein. The filter stages are designed to remove a least a portion of the contaminants present in the gas flowing through them. The apparatus can also include a flow controller for distributing the gas flow among the filter stages. In one embodiment, the controller may consist of a diffuser plate. The invention also provides a sampling tube orifice for gas flow control in a system or method of the invention. In another embodiment, an apparatus for removing contaminants from a gas in a clean room comprises a filter unit having at least two parallel filter stages, which are used to remove a portion of the contaminants in the gas as it passes through the apparatus.

Abstract: A uniform aerosol deposit sampling device includes a first housing and a second housing. The first housing has an air inlet and a first chamber. The second housing has an air outlet, an second chamber, a filter holder and a flow guiding portion. The filter holder is provided for securing an air-penetratable supporting pad and a filter media. The flow guiding portion is a substantially conical and gradually narrowing. The flow guiding portion has a semi-conical angle ranged from 15 to 85 degrees. So, the flow guiding portion makes the entire air flow smooth and evenly distributed. The aerosols will be evenly distributed and uniformly deposited on the filter media. And, it is easy to evaluate the amount and composition of the aerosols.

Abstract: A modified liquid impingement unit is configured to automatically maintain a volume of buffer solution within a determined range, the buffer solution used to collect airborne particles from an impinging airflow. The liquid impingement unit includes a first end of an air nozzle and a first end of a vacuum tube sealed within collection vessel. A fluid delivery tube is positioned within the vacuum tube such that a first end of the fluid delivery tube is also positioned within the sealed collection vessel. External to the sealed collection vessel, the fluid delivery tube branches from the vacuum tube through an aperture in the vacuum tube. The vacuum tube is coupled to a vacuum pump and the fluid delivery tube is coupled to a fluid pump. A control module provides control signals to the fluid pump such that the fluid pump delivers a second volume of buffer solution from a buffer solution container to the collection vessel via the fluid delivery tube.

Abstract: Embodiments of the invention generally related to a method and apparatus foe scanning a v-bank filter. In one embodiment, an apparatus for scanning a v-bank filter includes a hollow body having first and second ends. An outlet, formed at the second end of the body, is adapted for coupling a testing device to an interior volume of the body. A plurality of holes are formed through the body and are fluidly coupled to the interior volume. In another embodiment, a method for scanning a v-bank filter includes inserting a probe having a plurality of sample ports into a filter adjacent a filter pack, and traversing the probe along the filter pack. In yet another embodiment, a method for scanning a v-bank filter includes scanning a slot of a v-bank filter with a probe, and collecting samples of gas passing through the filter and into the probe.