Abstract: A system for making a biochemical assay of each of plurality of provided specimens, comprising: a plurality of receptacles, a sensor for providing a resistance, a mechanism and a controller.

Abstract: A clinical analyzer where incoming samples are partitioned into groups in accord with the length of time required for the assay to be completed or in accord with the pattern of reagent addition(s) taken with length of time required for the assay to be completed. Medium length time assays are completed, removed from a reaction carousel and replaced by shorter length time assays during a single operational cycle in which longer length assays are also completed.

Abstract: A volume-adjusting insert for sample vessels comprises an elongated body with a septum seal on one end and a seal surface on the outside of the body. A through-chamber in the body provides a receiving chamber for a hypodermic needle inserted into the septum. The seal surface of the insert defines a reduced-volume sample chamber comprising the through-chamber and the vessel chamber portion of the sample vessel below the insert, or alternatively, below the seal surface. Sample fluid injected into, or withdrawn from, the insert communicates with the through-chamber and the lower vessel chamber. The device is particularly useful in converting multi-well microplates to low sample-volume vessels for automated sampling and testing, and allows the hydraulic pressure generated by a hypodermic needle to transport the sample fluid through the sample vessel and out of a bottom-extraction element.

Abstract: An aspirating system for caps of sample containers including a suction duct, a partial-vacuum space formed by a collecting container, and a blower. The blower, when operated, produces a partial vacuum in the collecting container. The container is fitted at its lower side with a closing device.

Abstract: The present invention provides microfluidic devices, systems and methods for using the same, which facilitate the introduction of fluid to and from a microfluidic channel located within the microfluidic devices.

Abstract: A method for calibrating a clinical analyzer having a dispenser, and for automatically aligning the dispenser of the clinical analyzer includes loading a calibration element at a portion of the clinical analyzer; moving a dispenser of the clinical analyzer in a pre-determined direction (Y) to a position over the calibration element; measuring the height (Z) from the dispenser to the calibration element and determining a position coordinate (Yi, Zi); storing the position coordinate (Yi, Zi); determining a maximum height (Zmax) for the dispenser positioned over the calibration element defined as position coordinate (Yopt, Zmax); and storing the position coordinate including the maximum height (Zmax) for the dispenser positioned over the calibration element.

Abstract: A method for improving the fluid dispense rate in a metering system utilizing speed includes the steps of modifying the fluid flow rate profile during a portion thereof so as substantially increase or decrease the speed of the motor during certain portions of a metering cycle in order to improve the efficiency of the metering system. For a variable speed pump producing a sinusoidal speed profile, the pump motor speed can be increased to increase the dispense velocity during the beginning and end of the dispense phase to reduce perfusion and improve metered volume precision or a motor speed profile can be applied which is inverted relative to that of the variable speed pump to produce a constant velocity flow. Alternately or in addition to the above, the home position of the variable speed pump can be shifted to produce fluid velocity during the entirety of a dispense portion of a metering system cycle.

Abstract: An injection pump assembly 10 in a chemical delivery system for simultaneously delivering reagents into a combinatorial reactor system having multiple injectors. The assembly 10 has a plurality of injectors 12, each injector 12 being in fluid communication with one of the multiple reactors. Each injector 12 has (1) a pump 14 in which a plunger 18 sealingly moves to ingest, store and discharge a flushing solvent 20; (2) a pipette assembly 22 for loading, storing, and discharging one or more reagents into one of the reactors in the combinatorial reactor system, first and second reservoirs for retaining some of the reagents; (3) one or more hollow needles 32, each for selectively delivering a reagent 24 to the first 28 or the second 24 reservoir; (4) a first valve 34 positioned downstream of the first 28 reservoir; and (5) a second valve 36 positioned downstream of the second 30 reservoir. When each valve 34, 36 is in a closed position, the reagents 24, 48 can be stored in isolation from each other.

Abstract: The invention provides an integrated sample-processing system and components thereof for preparing and/or analyzing samples. The components may include a transport module, a fluidics module, and an analysis module, among others.

Abstract: The present invention, provides a flow cytometry apparatus for the detection of particles from a plurality of samples comprising: means for moving a plurality of samples comprising particles from a plurality of respective source wells into a fluid flow stream; means for introducing a separation gas between each of the plurality of samples in the fluid flow stream; and means for selectively analyzing each of the plurality of samples for the particles. The present invention also provides a flow cytometry method employing such an apparatus.

Abstract: A method and apparatus are provided for automatically sensing the presence (or absence) of spot dispensers such as pins in various possible mounting locations in the printhead of a microarray spotting instrument. Pin-location data obtained by the method and apparatus is provided to the computer controller of the instrument, which uses the data to control the motion of the printhead during operation of the instrument. A pin detection apparatus includes one or more sensor elements that automatically sense possible pin locations in the printhead for the presence of pins. The sensor elements are preferably arranged in an array corresponding to the array of pin locations in the printhead so that pin detection at each pin location can be performed simultaneously. Various types of sensor elements can be used to locate pins in a printhead. For example, sensors can be used that are remote from or attached to a printhead.

Abstract: The present invention, provides a flow cytometry apparatus for the detection of particles from a plurality of samples comprising: means for moving a plurality of samples comprising particles from a plurality of respective source wells into a fluid flow stream; means for introducing a separation gas between each of the plurality of samples in the fluid flow stream; and means for selectively analyzing each of the plurality of samples for the particles. The present invention also provides a flow cytometry method employing such an apparatus.

Abstract: A method for dispensing droplets of a liquid to a microsystem in the form of a disc comprising a target area (TA0I) in its surface, said disc preferably being a microfluidic disc comprising a microchannel structure with an inlet port that is a target area (TA0I). The method is characterized by comprising the steps of: i) providing (1) said disc which has a triggering mark, and (2) a dispenser arrangement comprising: a) a spinner for rotating the disc around its axis, b) a drop dispenser permitting dispensation of droplets to inlet port I, c) a fixed trigger position outside the disc, and d) a controller which is capable of triggering the dispensation of a droplet into (TA0I) as a function of the triggering mark passing the trigger position, ii) placing the disc in the spinner and programming the controller with values for dispensing parameters that will give dispensation of the droplets to TA0I, iii) dispensing the droplets. The invention also comprises the dispenser arrangement as such.

Abstract: A method and apparatus for controlling a stream of liquid and air segments wherein the liquid and air segments are selectively aspirated into a first fluid conduit in a plurality of cycles, each cycle beginning with the aspiration of a first air segment and ending with the aspiration of a final air segment. The liquid and air segments are then transferred from the first fluid conduit to a second fluid conduit. The volume of the final air segment of each cycle is then adjusted after the final air segment has moved into the second fluid conduit. Next, the liquid segments and the air segments of each cycle are transferred from the second fluid conduit to a third fluid conduit. The volume of the first air segment of each cycle is then adjusted after the first air segment has moved into the third fluid conduit.

Abstract: The invention relates to an appliance for opening and closing a reagent-container stopper in a partially or fully automatic analysis apparatus, and to the method, which is applied by means of this appliance, for opening and closing a reagent-container stopper in a partially or fully automatic analysis appliance.

Abstract: A work station for simultaneously performing multiple assays includes a base structure, a receptacle rack assembly received within a receptacle rack well formed in the base structure, a pipette tip rack assembly received within a pipette tip rack well formed in the base structure, a multiple conduit substance transfer device, and substance transfer device positioning structure. The receptacle rack assembly holds a plurality of receptacles in which a plurality of individual assays are performed, and the pipette tip rack assembly holds a plurality of contamination limiting pipette tips. The substance transfer device is capable of simultaneously dispensing substances into two or more receptacles or simultaneously removing substances from two or more receptacles. Alternatively, the substance transfer device is capable of simultaneously dispensing substances into two or more receptacles, and, at about the same time, simultaneously removing substances from two or more receptacles.

Abstract: An automated immunostaining apparatus having a reagent application zone and a reagent supply zone. The apparatus has a carousel slide support supporting a plurality of slide supports thereon, and drive means engaging the carousel slide support for consecutively positioning each of a plurality of slide supports in the reagent application zone. The apparatus also has a carousel reagent support having a plurality of reagent container supports thereon, and drive means engaging the carousel for rotating the carousel and positioning a preselected reagent container support in the reagent supply zone. The apparatus also has a reagent delivery actuator means positioned for engaging a reagent container positioned on a container support.

Abstract: An apparatus for the isolation of cell clusters that are either embedded or transported is preferably used for the isolation of the insulin-producing pancreatic islets of Langerhans, but it also can be used for the isolation of other types of cell clusters and particles in fluids as well. The apparatus employs digital imaging of the cell suspension on either a plane surface or in a capillary tubing, wherein a digital camera scans the cell suspension.

Abstract: A system for detecting and analyzing patient sample quality and/or analytes, while the sample is in the metering tip used to aspirate the sample liquid from an original patient sample container, and also to dispense the liquid onto a slide test element. Spectrophotometric analysis may be done on the sample liquid while it is still in the tip which has been converted into a cuvette. One technique for such analysis is by scanning the cuvette for transmittance in a light-tight enclosure. Near-infrared and adjacent visible radiation may be used, and the absorption spectra of the liquid detected and analyzed. A possible aspect of the present invention relates to enhancing throughput of an analyzer by conducting a sample quality measurement in a process that is parallel to the main analyzer timing cycle.

Abstract: Devices and methods for controlling and monitoring the progress and properties of multiple reactions are disclosed. The method and apparatus are especially useful for synthesizing, screening, and characterizing combinatorial libraries, but also offer significant advantages over conventional experimental reactors as well. The apparatus generally includes multiple vessels for containing reaction mixtures, and systems for controlling the stirring rate and temperature of individual reaction mixtures or groups of reaction mixtures. In addition, the apparatus may include provisions for independently controlling pressure in each vessel, and a system for injecting liquids into the vessels at a pressure different than ambient pressure. In situ monitoring of individual reaction mixtures provides feedback for process controllers, and also provides data for determining reaction rates, product yields, and various properties of the reaction products, including viscosity and molecular weight.

Abstract: A microvascular network device comprising: a substrate; at least one microchannel; at least one opening to the microchannel for sample entry; at least one opening to the microchannel for sample exit; and an aspirator which causes the sample to traverse the microchannel.

Abstract: Methods and systems for determining a dissolution profile of a sample material, and for solubilization screening of a library defined by an array comprising multiple sample materials are disclosed. The methods and systems are particularly advantageous for sampling and evaluation of very small samples, and can be advantageously applied in connection with evaluation of drug candidates.

Abstract: A fluidics station is described that includes a housing that accepts removable modules, where each of the removable modules includes; a holder that receives a probe array cartridge, where the probe array cartridge includes a chamber that is fluidically coupled to fluid transfer apertures; a transport mechanism that reversibly transports the holder and the probe array cartridge between a first position and a second position; alignment pins constructed and arranged to engage one or more alignment features of the probe array cartridge, where the probe array cartridge is in the second position; and a needle constructed and arranged to interface with each of the fluid transfer apertures.

Abstract: A new method and system for transporting and sorting multiple reagent packs used in conjunction with an immunodiagnostic instrument is provided. The new system includes a multiplicity of reagent packs; a gantry movably mounted on a rack structure for carrying a gripper mechanism, wherein the gripper mechanism has gripping jaws for engagement with the reagent pack; a power assembly for actuating the respective movement of the gantry, the gripper mechanism and the gripping jaws; a storage nest having a multiplicity of compartments, each adapted for storing a one of the respective reagent packs; and a pipetting nest having a multiplicity of compartment, each adapted for retaining a respective one of the reagent packs for simultaneous pipetting. Methods of using the system and a novel reagent pack used in connection with the new system are also provided.

Abstract: A blood cell detector includes an orifice section having a single orifice, a first supplying section for supplying a first blood specimen into the orifice section, a second supplying section for supplying a second blood specimen into the orifice section, and first and second electrodes provided on opposite sides of the orifice for detecting a change in impedance of each of the first and second blood specimens when the first and second blood specimens are selectively caused to pass through the orifice.

Abstract: A flow cell and flow cytometer in which a nozzle at the end of a flow channel is disposed on a removable substrate held at a registered location on a flow cell. Other elements including illumination optics, light collection optics, and the flow cell may then be positioned at fixed locations and would not require subsequent periodic adjustment. The registered location for positioning the nozzle allows removal and replacement of the nozzle key with the nozzle subsequently positioned in the identical location.

Abstract: A method and apparatus for processing coagulation studies, chemistry procedures and the like, the apparatus including a container having a space for containing a body fluid sample therein, a covered opening and being provided with optically clear sides and a uniform cross-sectional configuration over at least a portion of the container, the cover being pierceable to permit the selective addition of reagents to be delivered into the container space, and the apparatus and method facilitating carrying out analytical procedures on body fluid sample when it is contained in the container. The apparatus further including instrumentation for optically reading and analyzing the fluid sample and adding appropriate reagents while the sample it is in the container.

Abstract: Embodiments of the present invention are directed to an improved chemical synthesis apparatus for performing chemical synthesis such as nuclei acid synthesis in a plurality of reaction wells or cells in an efficient manner. The apparatus employs dispenser heads that each include a cluster of nozzles which are fluidicly coupled to a plurality of reagent sources for dispensing different reagents through the single dispenser head. Because each dispenser head is capable of dispensing a plurality of different reagents, the apparatus can perform simultaneous synthesis in a plurality of cells at a high throughput without complex and elaborate control of movement of the dispenser heads relative to the cells.

Abstract: The apparatus for analysis of physiological fluids of the invention contains equipment for automatic introduction of reference fluids to a sample aggregate inlet of the apparatus. The apparatus also contains equipment for analyzing the samples.

Abstract: In order to provide an automatic testing apparatus with improved reliability of test results, capable of conducting automatically such operations as sterile testing, microorganism limit testing, insoluble particulate measurement testing, divided portion testing for chemical analysis and chemical reaction testing, etc., and capable of accommodating changes in the specimen or the test container with each sample as well as changes in operating procedures with each sample so as to eliminate the possibility of human error and prevent contamination of the operating environment by human hands, the automatic testing apparatus of the present invention prepares a sample by mounting a set of various pieces of equipment including the specimen or test containers required to be changed with every sample atop a same work base and providing that work base as a unit to within the operating range of a robot, with the robot then handling the various pieces of equipment atop the work base to prepare the sample.

Abstract: The drop-by-drop evaporation of a liquid or solution is controlled by monitoring the disappearance of each successive droplet and by actuating the deposition of the next droplet until the desired volume is deposited. In the case of a solution, non-volatile residue (NVR) is collected on a deposition surface plate as a relatively small mound. One of a variety of methods may be employed to measure the evaporative behavior of each droplet and to key the deposition procedure. The process is preferably carried out employing a clean deposition surface plate that is maintained at or below the boiling point of the particular liquid or solvent being deposited. The environment is preferably controlled so that inadvertent contamination is precluded from interfering, and thus the method permits the automatic, micro-processor controlled evaporation of liquids with the resultant deposition of non-volatile residues from solutions within relatively short periods of time.

Abstract: In a testing system for chemical substances or substance mixtures, especially for potential plant protection compositions, the chemical substance to be tested or the substance mixture to be tested is applied to a test specimen, especially to plants or parts of plants. When a predetermined period of time has elapsed, the test specimen is examined for the activity of the substance or substance mixture. For this purpose, first of all a type of test specimen is selected from a stock of test specimens, and the substances to be tested are selected from a stock of substances to be tested. The selected type of test specimen and the selected substances are identified (BC1, BC2) by means of a machine-readable code and those codes are supplied to a memory unit (12).

Abstract: An injection pump assembly 10 in a chemical delivery system for simultaneously delivering reagents into a combinatorial reactor system having multiple injectors. The assembly 10 has a plurality of injectors 12, each injector 12 being in fluid communication with one of the multiple reactors. Each injector 12 has (1) a pump 14 in which a plunger 18 sealingly moves to ingest, store and discharge a flushing solvent 20; (2) a pipette assembly 22 for loading, storing, and discharging one or more reagents into one of the reactors in the combinatorial reactor system, first and second reservoirs for retaining some of the reagents; (3) one or more hollow needles 32, each for selectively delivering a reagent 24 to the first 28 or the second 24 reservoir; (4) a first valve 34 positioned downstream of the first 28 reservoir; and (5) a second valve 36 positioned downstream of the second 30 reservoir. When each valve 34, 36 is in a closed position, the reagents 24, 48 can be stored in isolation from each other.

Abstract: Disclosed is to improve the reliability of and lower the cost for an automatic analyzing apparatus for analyzing a biological sample such as urine or blood, by integrating the mechanisms of a dispenser and an agitator to reduce the number of parts. In an automatic analyzing apparatus of the type for analyzing a sample by dispensing the sample and a reagent into a reaction container and by agitating and mixing the sample and the reagent, an agitating motor head is mounted on a sampling arm so that the sampling mechanism is also used as an agitating arm turning mechanism and a vertical moving mechanism. Water for cleaning the reaction container is injected by a reagent dispensing probe.

Abstract: A chemically analyzing apparatus includes a plurality of reaction containers, a reaction container holder for holding the plurality of reaction containers and for supplying a sample and reagent at predetermined positions, a plurality of reagent containers for holding reagent adapted to be supplied into the reaction containers, a reagent container holder provided above the reaction container holder, for holding the plurality of reagent containers, a measuring part for measuring physical properties of the sample, a liquid feed mechanism provided in a lower part of each of the plurality of reagent containers, for supplying a predetermined quantity of reagent from each of the reagent container into the associated reaction containers by means of the liquid feed mechanism.

Abstract: A microvolume liquid handling system includes a microdispenser employing a piezoelectric transducer attached to a glass capillary, a positive displacement pump for priming and aspirating transfer liquid into the microdispenser, controlling the pressure of the liquid system, and washing the microdispenser between liquid transfers, and a pressure sensor to measure the liquid system pressure and produce a corresponding electrical signal. Dispensing of a single sub-nanoliter drop can be detected in real time. As the result of dispensing the liquid in sub-nanoliter droplets, the dispensed volume can be precisely controlled. The dispenser automatically detects the liquid surface of the transfer liquid, automatically aspirate, analyze desired volume of the transfer liquid, dispense the transfer liquid without contacting the destination vessel or its contents, and automatically wash off the transfer liquid from dispensing system after each transfer.

Abstract: A system for making a biochemical assay of each of plurality of provided specimens, comprising: a plurality of receptacles, a sensor for providing a resistance, a mechanism and a controller.

Abstract: Device for filling, with a liquid medium (1), an analysis card (2) comprising a body (3) in which at least one reading cavity (3a) is formed, and an orifice (4) communicating with the cavity via at least one internal channel (7), with an external conduit (9) communicating with the orifice, this device comprising an evacuation device (50). It comprises: a connecting device (11) including on one side a joining piece (12) for leaktight and removable coupling to the free end (9a) of the open external conduit, and communicating directly on the other side with the evacuation device (50); a device (34) for closing and re-opening the external conduit.

Abstract: Devices and processes for the simultaneous transfer of liquids from a source container to a target container are disclosed. The source container includes a multitude of source sub-containers, and the target container includes a multitude of target sub-containers. The device includes a multitude of tubes arranged in a matrix, each tube having an entrance and exit.

Abstract: A fluid dispensing system and method includes a pump to aspirate and expel sample fluid, a fluid dispensing tip, and a metering station. The fluid dispensing tip includes a working fluid and an air gap where the air gap separates the working fluid from the sample fluid. The metering station receives a drop of sample fluid that is at least twice as large as the predetermined volume to ultimately be dispensed. The fluid dispensing tip then withdraws the predetermined volume of fluid from the sample fluid. Precise volumes are ascertained by prior knowledge of the geometry of the fluid dispensing tip and by using an imaging device to monitor an interface of either the sample fluid or working fluid with the air gap within the fluid dispensing tip. The system and method are capable of accurately dispensing very small volumes of sample fluid on the order of 10 picoliters. In addition, the system and method do not require large volumes of sample fluid to prime a pump mechanism.

Abstract: A fluid dispensing system and method includes a pump to aspirate and expel sample fluid, a fluid dispensing tip, and a metering station. The fluid dispensing tip includes a working fluid and an air gap where the air gap separates the working fluid from the sample fluid. The metering station receives a drop of sample fluid that is at least twice as large as the predetermined volume to ultimately be dispensed. The fluid dispensing tip then withdraws the predetermined volume of fluid from the sample fluid. Precise volumes are ascertained by prior knowledge of the geometry of the fluid dispensing tip and by using an imaging device to monitor an interface of either the sample fluid or working fluid with the air gap within the fluid dispensing tip. The system and method are capable of accurately dispensing very small volumes of sample fluid on the order of 10 picoliters. In addition, the system and method do not require large volumes of sample fluid to prime a pump mechanism.

Abstract: A sample handling method, in which the information on the sample to be examined is transferred throughout the entire measuring process by transferring the sample cup. The sample cups are handled in two independently operating drums, in which case at least two different handling phases can be carried out simultaneously in the measuring device. The diagnostic measuring device comprises a cassette drum, on the circumference of which the sample cup cassettes containing sample cups have been placed. The sample cup is fed to the first handling drum, which is simultaneously an incubation drum. After that the sample cup is transferred to a second handling drum, where washing, drying, measuring and discharge of the sample cup are carried out. The drums have been placed near each other, overlapping so that the transfers of the sample cup can be performed directly from one drum to another by means of transfer plungers.

Abstract: In a preferred embodiment, a small volume pipettor, including: a plurality of pistons; a plurality of liquid delivery needles; motive means to cause one of the pistons to move axially within one of the needles to cause a liquid to be selectively drawn into and discharged from the needle; sealing apparatus disposed around the pistons to effect sealing of upper ends of the needles; assembly apparatus in which the needles and the sealing apparatus are disposed; and apparatus to permit the assembly apparatus to be removed from the pipettor as a one-piece unit. Further provided are novel apparatus to seal upper ends of the needles around the pistons.

Abstract: A fluid sampling apparatus and associated fluid analyzer sample process fluids used in semiconductor manufacturing at a plurality of measurement points. The fluid sampling apparatus includes a first nozzle assembly having a plurality of outlet nozzles. The plurality of outlet nozzles are connected to lines supplying the process fluids. A second nozzle assembly is installed above the first nozzle assembly and includes an inlet nozzle connected to an apparatus for measuring a contamination level of the process fluids. A motor is connected to the second nozzle assembly to align a selected outlet nozzle with the inlet nozzle. A pneumatic cylinder is coupled to the first nozzle assembly to connect the selected outlet nozzle with the inlet nozzle. In this manner, it is possible to measure the contamination level of process fluids supplied at a plurality of measurement points by using a single measuring apparatus.

Abstract: A two-pin liquid sample dispensing system is provided. The two-pin dispensing system comprises a pair of separately movable pins for holding a droplet of liquid therebetween. Each pin includes a tip spaced predetermined distance from the other pin to define a sample acquisition region. The pins acquire and hold a droplet of the liquid sample in the sample acquisition region formed in the space between the tips and apply the droplet to a selected sample handing system. The distance between the tips is variable to accommodate different liquid samples having varying physical properties and to vary the volume of the acquired droplet.

Abstract: A droplet dispensing system for forming and dispensing droplets of a liquid sample is provided. The droplet dispensing system is fabricated on the tip of a dispensing pin. The tip of the dispensing pin includes a droplet ejection nozzle, a filling channel, a chamber and an actuator for ejecting droplets on demand. The system further includes a holder for mounting the dispensing pin. The holder also contains a control circuit for activating the actuator.

Abstract: Apparatus and methods for aspirating and dispensing reagents are provided. Aspirating of reagents is accomplished by a probe, a vial insert and reagent vial according to the present invention wherein a seal is formed between the probe and the vial insert when the probe engages the vial insert. Dispensing of reagents is accomplished by a probe and a probe dispense and wash station according to the present invention wherein a seal is formed between the probe and the vial insert when the probe engages the probe dispense and wash station.

Abstract: An automated in situ heat induced antigen recovery and staining method and apparatus for treating a plurality of microscope slides. The process of heat induced antigen recovery and the process of staining the biological sample on the microscope slide are conducted in the same apparatus, wherein the microscope slides do not need to by physically removed from one apparatus to another. Each treatment step occurs within the same reaction compartment. The reaction conditions of each reaction compartment for treating a slide can preferably be controlled independently, including the individualized application of reagents to each slide and the individualized treatment of each slide. The reagents are preferably held in a reagent dispensing strip similar to a “blister pack”.

Abstract: An apparatus for imprinting cassettes (1) and/or specimen slides, having a printing head (2) and a delivery device (3) for the cassettes (1) and/or specimen slides, is described. A pivot device (5) is provided for alignment of the printing head (2) with differently inclined printing planes (4) or for alignment of differently inclined printing planes (4) with the printing head (2).

Abstract: A method and apparatus for dispensing precise quantities of reagents is disclosed including a positive displacement syringe pump in series with a dispenser, such as an aerosol dispenser or solenoid valve dispenser. The pump is controlled by a stepper motor or the like to provide an incremental quantity or continuous flow of reagent to the dispenser. The pump and dispenser are operated in cooperation with one another such that the quantity and/or flow rate of liquid dispensed by the dispenser can be precisely metered substantially independently of the particular operating parameters of said dispenser to attain a desired flow rate, droplet size or mist quality, droplet frequency and/or droplet velocity.