Abstract: A collection apparatus comprises a nozzle comprising an inlet for receiving at least a portion of a gas stream and an outlet, and at least one sorbent trap having an inlet in fluid communication with the outlet of the nozzle, wherein the sorbent trap comprises one or more collection media configured to collect at least one of a metal, an element, and a halogen present in the portion of the gas stream.

Abstract: Certain embodiments described herein are directed to devices, systems and methods that are configured to control flow of an explosive carrier gas in a sampling system. In some examples, a flow control device configured to provide release of explosive carrier gas in less than an explosive amount to void space in the sampling system is described. Systems and methods using the flow control device are also disclosed.

Abstract: The detection system of the first preferred embodiment includes a detector, having a wide dynamic range, that receives photonic inputs from an interrogation zone and produces an analog signal; and an analog-to-digital converter (ADC), having a high bit resolution, that is coupled to the detector and converts an analog signal to a digital signal. The digital signal includes an initial data set of the full dynamic range of the input signals from the flow cytometer sample. The method of extracting and analyzing data from a flow cytometer system of the first preferred embodiment preferably includes the steps of: collecting a full dynamic range of input signals from a flow cytometer sample; recognizing and annotating aggregate particle events; and storing an initial data set and an annotated data set of the full dynamic range of the input signals from the flow cytometer sample.

Abstract: A solid phase extraction apparatus includes a sample adsorption assembly and a needle. The adsorption assembly includes a housing, a distal housing opening, and an adsorption bar disposed in the housing. The adsorption bar includes an outer surface coated with an adsorption material. The adsorption bar is located between the distal housing opening and a proximal housing opening. The outer surface is spaced from an inner housing surface, wherein the adsorption assembly includes an adsorption region between the inner housing surface and the outer surface. The adsorption assembly establishes a fluid flow path from the distal housing opening, through the adsorption region along a longitudinal direction, and to the proximal housing opening.

Abstract: The present disclosure concerns embodiments of a sampling apparatus that utilizes one or more cyclone separators to collect airborne particles from the atmosphere. In one representative embodiment, the sampling apparatus includes a collection-vessel retaining member that is adapted to be removably coupled to a collection vessel. The retaining member has an air-inlet conduit for permitting air to flow through the open end of the collection vessel and an air-outlet conduit for permitting air to exit the open end of the collection vessel. The air-inlet conduit and the air-outlet conduit are configured to cause air flowing into the collection vessel to establishes a cyclonic flow path, which causes airborne particles to separate out from the air stream and collect in the collection vessel.

Abstract: In an embodiment, a wetted wall cyclone comprises a cyclone body including an inlet end, an outlet end, an inner flow passage, and an inner surface defining an inner diameter. In addition, the wetted wall cyclone comprises a cyclone inlet tangentially coupled to the cyclone body. The cyclone inlet includes an inlet flow passage in fluid communication with the inner flow passage. Further, the wetted wall cyclone comprises a skimmer extending coaxially through the outlet end of the cyclone body. The skimmer comprises an upstream end disposed within the cyclone body, a downstream end distal the cyclone body, and an inner exhaust passage in fluid communication with the inner flow passage. Still further, the wetted wall cyclone comprises a first annulus positioned radially between the upstream end and the cyclone body having a radial width W1 between 3% and 15% of the inner diameter of the cyclone body.

Abstract: Environmentally friendly solvents used to dissolve or remove residues and/or substances from substrates wherein the residue and/or substance is contacted with a Generally Recognized As Safe solvent to dissolve the residue and/or substance in the solvent followed by the extraction of the residue and/or substance from the solvent such as by contact with carbon dioxide.

Abstract: A portable multi-tube air sampler device for capturing samples of trace elements in a suspected contaminated environment which includes a plurality of sample tubes for collecting sample trace elements, parallel inlet and outlet manifolds which minimize the length of the sample inlet path while utilizing short straight sample tubes, a hinged retainer bar mechanism which allows for easy removal and replacement of the various sample tubes, and a removably attachable controller unit which can be installed on the exterior portion of the carrying case for controlling the operation of the sampling protocol. Other embodiments include heated inlet manifold and sample intake paths to prevent contamination accumulation and carryover, a clean cycle option with a filter valved into the inlet flow path to enhance the purging cycle, and a mechanism for converting the present device to a desorbing auto sampler configuration. The present system likewise incorporates a purging cycle prior to each sampling cycle.

Abstract: A pre-concentration device and a method are disclosed for concentrating gaseous vapors for analysis. Vapors sorbed and concentrated within the bed of the pre-concentration device are thermally desorbed, achieving at least partial separation of the vapor mixtures. The pre-concentration device is suitable, e.g., for pre-concentration and sample injection, and provides greater resolution of peaks for vapors within vapor mixtures, yielding detection levels that are 10-10,000 times better than direct sampling and analysis systems. Features are particularly useful for continuous unattended monitoring applications. The invention finds application in conjunction with, e.g., analytical instruments where low detection limits for gaseous vapors are desirable.

Abstract: A device for use with a detection means and a solvent source for sampling low volatility hazardous chemicals within a sample matrix is comprised of a sonicator having a probe for providing mechanical agitation to the sample matrix; means for transporting solvent gas from the solvent source to the sample matrix; means for transporting sample gas from the sample matrix to the detection means; and a heating element for heating the sample gas, solvent gas, and sample matrix. The device may include a thermocouple for providing a temperature reading. It also may include a plurality of interchangeable probe tips of different shapes.

Abstract: A quantitative fit test (QNFT) system and method for assessing the biological fit factor (FF) performance of respiratory protective devices. The biological QNFT system includes the following three main elements: an aerosol generation system; an exposure chamber; and an aerosol sampling subsystem. The aerosol sampling subsystem includes an aerosol spectrometer that counts particles in discrete size units ranging from 0.5 to 20 micrometers (?m) making it possible to obtain several size-specific FF measurements from a single respirator fit test. A virtual impactor in the aerosol generation system increases the number of challenge particles in the primary target size of interest (1 to 5 ?m) and increases the sensitivity of the method allowing FF values of up to one million to be measured without the need to correct for in-mask background particles.

Abstract: A liquid separator with at least one flow passageway is used to detect and remove the presence of entrained liquids from natural gas during spot sampling procedures prior to analysis of the sample by a gas chromatograph. In one embodiment, the at least one flow passageway directs at least a portion of the gas flow to impinge upon the inside surface of a sight glass and swirl around in a chamber which may cause droplets of liquid to coalesce on the inside of the sight glass and may cause a fog to form inside the chamber, all of which make it easier to see the existence of liquids in the natural gas. The at least one flow passageway is less expensive to fabricate than some prior art flow directing elements.

Abstract: A cartridge provides reagents for a biosensor system. The cartridge has at least two containers, the upper sides of which are each sealed by a foil in an airtight and waterproof manner. The at least two containers have sloped bases, the slopes of which are aligned identically. The cartridge can be coupled to a biosensor system in that a hollow needle which is fixed at the sensor system extends through the foil of the at least one of the at least two containers in a coupled state. The end of the hollow needle is positioned in the vicinity of the base of the corresponding container. A drying agent for the water-free storage or for the ventilation of reagents is provided in the cartridge.

Abstract: A disk-based fluid sample separation device including at least one air vent forming a part of a flow channel pattern on a microfluidic disk is disclosed. The fluid sample separation device is provided with an air vent sealing cover having at least through hole and is placed on the top surface of the disk. The air vent sealing cover is rotated with respect to the disk either at a first position or a second position. At the first position, the hole of the air vent sealing cover is in correspondence to the air vent of the flow channel pattern to control the sample liquid delivery. At the second position, the air vent of the flow channel pattern is closed. The flow channel pattern includes at least one sample storage reservoir, at least one sample processing reservoir, and at least one communication channel which is in fluid communication between the sample storage reservoir and the sample processing reservoir. In alternative, the status of the hole of the air vent sealing cover is controlled by a control unit.

Abstract: An inline virtual impactor comprising an outer housing having a housing inlet, a housing inner surface, a major flow outlet and a minor flow outlet; a flow accelerator member disposed in the upstream portion of the outer housing; and a flow stabilizer member disposed within the outer housing downstream of the flow accelerator member, wherein the disposition of the flow accelerator creates an annular flow passage between the flow accelerator and the outer housing, and wherein a flow divider that is at least partially downstream of the flow stabilizer member effects splitting of the flow stream entering the housing into major and minor flows. The minor flow comprises primarily particles having a size greater than a cutpoint size and the major flow comprises primarily particles smaller than the cutpoint size. The inline virtual impactor may further comprise an aspiration section located upstream of the flow accelerator member.

Abstract: The system includes at least one sampler including a body having a hollow interior accessed through holes in the body and optionally a slide which can selectively cover and expose the holes in the body. A stand is provided made of a base and a floor. The base includes at least one recess therein. The recess is configured to support the sampler therein so that the sampler can be held by the stand while sampling an airspace at a particular location. The floor can be separated at least partially from the base in a removably attachable fashion to provide selective access to a hollow inside. A sampler can be placed within this hollow inside space and resealed so that the stand doubles as a shipping container for the sampler after collection of an air sample.

Abstract: An inlet apparatus is disclosed. The apparatus may include a first conduit for sampling, and a second and third conduit for directing flow throughout the inlet apparatus. Flow may be induced in two opposite directions through the second conduit, which affect the flow of gas through the first conduit for sampling. The various conduits of the apparatus may be connected to a device for inducing flow in different directions. The duration of the flow in a particular direction affects the amount of sample gas that enters a detection device.

Abstract: A transfer structure for droplet-based microfluidic analysis is characterized by a first conduit containing a first stream having at least one immiscible droplet of aqueous material and a second conduit containing a second stream comprising an aqueous fluid. The interface between the first conduit and the second conduit can define a plurality of apertures, wherein the apertures are sized to prevent exchange of the first and second streams between conduits while allowing lossless transfer of droplets from the first conduit to the second conduit through contact between the first and second streams.

Abstract: A wetted wall cyclone system for sampling an aerosol. In an embodiment, the system comprises a cyclone body including an inlet end, an outlet end, and an inner flow passage extending therebetween. In addition, the system comprises a cyclone inlet tangentially coupled to the cyclone body proximal the inlet end. The cyclone inlet includes an inlet flow channel in fluid communication with the inner flow passage of the cyclone body. Further, the system comprises a skimmer coaxially coupled to the outlet end of the cyclone body. The skimmer comprises a separation end extending into the outlet end of the cyclone body, a free end distal the outlet end of the cyclone body, and an inner exhaust channel in fluid communication with the inner flow passage of the cyclone body. Still further, the system comprises means for reducing the temperature of at least a portion of the cyclone body.

Abstract: A conduit system comprising: a conduit formed by a surface extending from a first end to a second end, wherein the conduit is configured to channel a mixture stream from the first end to the second end; and a plurality of fluid delivery features disposed along the conduit between the first end and the second end, wherein each fluid delivery feature is configured to deliver a conditioning fluid into the conduit in an annular formation in a direction angled towards the second end in the same direction as the flow of the mixture stream, thereby providing a sheath of conditioning fluid between the conduit surface and the mixture stream.

Abstract: The present invention relates to a collection device for a substance, and methods related to collecting thereof.

Abstract: A test system for taking a sample of a constituent on a surface utilizing a fluid source includes an upper body and a concomitant mating lower body that includes an aperture in a portion thereof. A central fiber portion and a support extend through upper body aperture to provide a consistent surface for contacting the surface to be tested.

Abstract: A novel multi-gas passive sampler is described, whereby different collection media are packed into one passive sampler to collect a variety of air pollutants (or groups of air pollutants) at the same time. By comparison with known commercially available passive samplers—in which only a single collection medium is used to collect a single air pollutant of or group of air pollutants—the MGPS is more cost effective, convenient to use and more environment-friendly.

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: It is a subject of the present invention to provide a novel polymer; a filler for measuring a perfluoro compound having an acidic group at terminal which comprises said polymer; a column filled with said filler; and a measuring method for a perfluoro compound having an acidic group at terminal by using said column; as well as a filler for measuring a drug comprising the above-described polymer; a column filled with said filler; and a measuring method for a drug by using said column.

Abstract: A detector for the detection for trace vapors and particles in the air that includes a housing; a well formed in the housing; a heated filter positioned across the well; a source delivering sampled air substantially perpendicular to the open end of the well on a first side of the filter; a source to supply dry air across the first side of the filter; a detector line in communication with the at least one well on a second side of the filter; and a second dry air source for supplying air to the second side of the filter at a pressure below atmospheric pressure. An automatic inspection station that includes a vibrator for vibrating articles to be inspected. An automatic inspection station that includes a heating element positioned below an upper surface of the floor and an inlet positioned above the floor.

Abstract: A fluidic device for separating different components of a sample, the fluidic device comprising a microstructured body and porous material covering at least a portion of a surface of the microstructured body.

Abstract: Disclosed herein are sample preparation devices, such as pipette tips useful for associating and releasing biological molecules.

Abstract: The present invention relates to systems and methods for minimizing or eliminating diffusion effects. Diffused regions of a segmented flow of multiple, miscible fluid species may be vented off to a waste channel, and non-diffused regions of fluid may be preferentially pulled off the channel that contains the segmented flow. Multiple fluid samples that are not contaminated via diffusion may be collected for analysis and measurement in a single channel. The systems and methods for minimizing or eliminating diffusion effects may be used to minimize or eliminate diffusion effects in a microfluidic system for monitoring the amplification of DNA molecules and the dissociation behavior of the DNA molecules.

Abstract: A method for determining sperm quality is provided. At least one first microfluidic region and at least one second microfluidic region are provided, which meet at a junction. The second microfluidic region includes a shrunk portion with a width sized to substantially allow only one sperm to pass therethrough. A detector is disposed at the shrunk portion. First and second flow fields are formed in the first and second microfluidic regions, respectively. The first and second flow fields have different directions at the junction. A semen sample is loaded at a semen sample loading end. At least one sperm moves in the first microfluidic region against the direction of the first flow field and at least one sperm moves in the second microfluidic region along the direction of the second flow field. The detector generates a signal upon one sperm in the semen sample passing through the shrunk portion.

Abstract: The present invention is a method and apparatus for contaminant detection in the food industry. Particularly, the method and apparatus involve collecting air samples containing aerosolized contaminate particles from a foodstuff and analyzing the sample for presence of a contaminate. Aerosol lab-on-a-chip and/or electronic nose devices are utilized for the detection of contaminant particles.

Abstract: A method of scanning a sample plate surface mask in an area adjacent to a conductive area using mass spectrometry is disclosed. The method comprises the steps of providing a sample plate including a mask applied with a rough surface to the electrically conductive surface to produce a sample site comprising a central portion formed from the electrically conductive surface and a marginal portion of the mask, preparing an analyte comprising mixing a biomolecule with an organic solvent, an aqueous solution, and a matrix selected from the group of ?-cyano-4-hydroxycinnamic acid and 3,5-dimethoxy-4-hydroxycinnamic acid; applying the analyte to the sample site; forming at least one crystal of the analyte in an area on the mask adjacent to the conductive area, and scanning the area on the mask adjacent to the conductive area with a laser beam.

Abstract: A high throughput apparatus and method for gaining access to and extracting internal tissue or structure of interest from a seed or plurality of seed is disclosed. In one aspect, an apparatus utilizes means to expose the internal tissue or structure and means to separate at least some of the exposed internal tissue or structure for collection and evaluation. In one aspect, a method utilizes some force or action to expose the internal tissue or structure and some force or action to separate the internal tissue or structure.

Abstract: A gas component collector comprises a filter assembly 3 comprising an adsorbent and an adsorbent holding plate having a first face, a second face and a plurality of holes that are bored through from the first face to the second face and are filled with the adsorbent adsorbing at least one gas component to be analyzed, the filter assembly satisfying (AL?V)2/L3?0.003 mm3 and V/AL?0.3, where V is a total volume of the adsorbent, A is a sum of an opening areas of the holes, and L is an average length of the holes, and a holding container 2 housing the filter assembly 3. On at least one of the holding container 2 a first opening portion for introducing gas and a second opening portion for allowing the introduced gas to be discharged are formed.

Abstract: A method and tube for separating a sample. The tube is configured to separate agglomerated or clumped material or other sample components having over a particular size from other smaller size portions of the sample. For example, blood clots may be separated from serum of a blood sample. The tube includes a chamber with a closed bottom and a sidewall extending upwardly from the bottom, and a sample inlet branch coupled to the chamber. A slit is positioned between the chamber and the sample inlet branch so that after a sample is placed into the sample inlet branch, a portion of the sample having a size smaller than the slit (e.g., liquid material) passes through the slit and into the chamber, and material in the sample having a size larger than the slit remains in the sample inlet branch.

Abstract: The present invention of collecting a gaseous sample employs a sealable container, an inlet mounted at a part of the container, an outlet mounted at another part of the container, an atomizing electrode mounted in the container, a primary refrigerator mounted adjacent to the atomizing electrode, an opposite electrode mounted in the container, an acicular capture electrode mounted adjacent to the opposite electrode, and a secondary refrigerator mounted adjacent to the capture electrode. Charged microparticles are prepared by chilling the gaseous sample and producing condensate of the same. Such charged microparticles are collected by the capture electrode with static electricity, and they are condensed by chilling them. This method prevents the capture electrode from spreading solution thereon.

Abstract: The present invention relates to an analytical tool including a plurality of flow paths 21 each including a detection cell 26 for detecting a particular component contained in a sample and configured to move the sample by capillarity, and a common path 22 connecting the plurality of flow paths 21 to each other. Each of the flow paths 21 includes a water stopper 29 for preventing the sample from flowing into the common path 22. Preferably, the water stopper 29 suppresses the movement of the sample by differentiating a cross sectional area at a target portion in a direction perpendicular to the sample flow direction from a cross sectional area at a portion near the target portion.

Abstract: A method for reducing corrosion product transport in a power producing facility. The method includes the steps of selecting a chemical dispersant adapted to reduce the deposition of corrosion products in the recirculation path, and using at least one chemical injector to inject the chemical dispersant into a fluid contained in the recirculation path during recirculation path cleanup to increase corrosion product removal.

Abstract: Methods, systems, and apparatus are provided for automated isolation of selected analytes, to which magnetically-responsive solid supports are bound, from other components of a sample. An apparatus for performing an automated magnetic separation procedure includes a mechanism for effecting linear movement of a magnet between operative and non-operative positions with respect to a receptacle device. A receptacle holding station within which a receptacle device may be temporarily stored prior to moving the receptacle to the apparatus for performing magnetic separation includes magnets for applying a magnetic field to the receptacle device held therein, thereby drawing at least a proton of the magnetically-responsive solid supports out of suspension before the receptacle device is moved to the magnetic separation station. An automated receptacle transport mechanism moves the receptacle devices between the apparatus for performing magnetic separation and the receptacle holding station.

Abstract: During the fabrication of microstructure devices, such as integrated circuits, particles may be analyzed by displacing or removing the particles from the device surface and subsequently performing an analysis process. Consequently, a well-defined measurement environment may be established after removal of the particles, which may be accomplished on the basis of nanoprobes and the like. Hence, even critical surface areas may be monitored with respect to contamination and the like on the basis of well-established analysis techniques.

Abstract: A device for the automatic extraction of chemical samples is provided. One or more chemical samples are extracted under automatic control for the controlled mixing, heating, cooling, shaking and dispensing thereof. The device includes a housing defining an open interior region. A rotating carousel is disposed within the housing, and a plurality of sample holders are mounted thereon. A plurality of sample storage tanks each contain a unique chemical sample, and a desired volume of at least one chemical sample is drawn from a respective one of the sample storage tanks to a respective at least one of the plurality of sample holders. The carousel is rotated so that the desired volume of the at least one chemical sample may be dispensed into a receptacle positioned adjacent the carousel. The at least one chemical sample may then be mixed, heated, cooled, shaken and/or vibrated within the receptacle prior to dispensing.

Abstract: An apparatus and a method for concentrating a target substance in a liquid has been invented. The apparatus comprises a first reservoir with inlet openings for introducing a fluid comprising a target substance into the first reservoir and a second reservoir separated from the first reservoir by a partition permeable to permit the fluid to traverse the partition while retaining the target substance in the first reservoir.

Abstract: Disclosed is a fluid sampling device comprising a plurality of inlet channels, each of which is arranged to receive an airflow from an associated direction, such that a sampling medium associated with a particular inlet channel is exposed to airflow from the associated direction.

Abstract: A water transport assembly, is provided including a housing having a first chamber therein, which is accessible through an opening in the housing. The housing additionally includes a sample inlet port and a sample outlet port, both of which are in fluid communication with the first chamber. A flat ion exchange membrane is attached to the housing in a plane over the opening in the housing, to seal the opening in a vapor tight seal. Water will pass through the membrane based upon the vapor pressure on each side of the membrane, to either dry or humidify sample passing through the first chamber. When the flat ion exchange membrane is a flat, thin ion exchange membrane it is preferable that the thin ion exchange membrane have a thickness of between about 0.1 and about 3.0 mils.

Abstract: The detection system of the first preferred embodiment includes a detector, having a wide dynamic range, that receives photonic inputs from the interrogation zone and produces an analog signal; and an analog-to-digital converter (ADC), having a high bit resolution, that is coupled to the detector and converts an analog signal to a digital signal. The digital signal includes an initial data set of the full dynamic range of the input signals from the flow cytometer sample. The method of extracting and analyzing data from a flow cytometer system of the first preferred embodiment preferably includes the steps of: collecting a full dynamic range of input signals from a flow cytometer sample; recognizing and annotating aggregate particle events; and storing an initial data set and an annotated data set of the full dynamic range of the input signals from the flow cytometer sample.

Abstract: A method of detecting particles during inspection is provided. The method includes establishing a security checkpoint including a detection system, wherein the detection system includes a chamber defining a passage and includes a plurality of jets. The method also includes passing an individual through the passage, enhancing a convection plume including particles from the individual by blowing air through at least one of the plurality of jets, and absorbing the particles in a preconcentrator including a filter encased in a frame having a high thermal conductivity. Moreover, the method includes evaporating the particles absorbed in the preconcentrator and using a detector to determine whether the particles are from at least one of an explosive material and a narcotic substance.

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: The present invention of collecting gaseous sample employs the sealable container, the inlet mounted at a part of the container, the outlet mounted at the other part of the container, the atomizing electrode mounted in the container, the primary refrigerator mounted at adjacent to the atomizing electrode, the opposite electrode mounted in the container, the acicular capture electrode mounted at adjacent to the opposite electrode, and the secondary refrigerator mounted at adjacent to the capture electrode. Charged microparticles are prepared by chilling gaseous sample and producing condensate of the same. Such charged microparticles are collected by the capture electrode with static electricity, and they are condensed by chilling them. This method prevents the capture electrode from spreading solution thereon.

Abstract: A dilution apparatus for diluting a gas sample. The apparatus includes a sample gas conduit having a sample gas inlet end and a diluted sample gas outlet end, and a sample gas flow restricting orifice disposed proximate the sample gas inlet end connected with the sample gas conduit and providing fluid communication between the exterior and the interior of the sample gas conduit. A diluted sample gas conduit is provided within the sample gas conduit having a mixing end with a mixing space inlet opening disposed proximate the sample gas inlet end, thereby forming an annular space between the sample gas conduit and the diluted sample gas conduit. The mixing end of the diluted sample gas conduit is disposed at a distance from the sample gas flow restricting orifice. A dilution gas source connected with the sample gas inlet end of the sample gas conduit is provided for introducing a dilution gas into the annular space, and a filter is provided for filtering the sample gas.

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.