Abstract: A thin film deposition apparatus is used for applying thin films onto substrates, such as large panel displays, as well as integrated circuit devices, and includes a source of an ionized gas that is intermixed with an aerosol prior to deposition. The ionized gas causes the aerosol particles to take on an electrical charge. The aerosol containing the charged particles is concentrated in a virtual impactor and then provided to a shower head or orifice that is used for depositing the aerosol material onto the substrate. The shower head can be moved in a selected pattern to uniformly deposit aerosol particles as a thin film on the substrate.

Abstract: A sampler for removing a sample of gas from a flue or stack utilizes virtual impactor principles, together with a gas jet ejector to insure that the surfaces are kept free of particles. The gas that is discharged from the sampler thus is not changed in character by contact with particles that may adhere to surfaces of the sampler.

Abstract: An impactor assembly comprises a base for supporting a plurality of cups that form impactor plates, and a nozzle above each of the cups through which a flow passes for classification. The cover is removable, and a test cover can be put into position for mounting in place and providing outlets connectable to pressure sensor for determining pressure drop across the nozzle plates at each impactor stage. The cover also is designed to be easily washed by having no blind cavities or moving parts on the cover, and the latch and other hinge assemblies are all supported on the base. The flow enters and exits the impactor without having external connections on the cover.

Abstract: A diesel particle virtual impactor sampler provides for a total flow through a virtual impactor after the flow passes through a classifier that removes particles substantially larger than the cutoff point of the virtual impactor. The virtual impactor has two outlets, one for minor flow and one for major flow. In a preferred embodiment, filters are used for separately filtering the major and minor flows and collecting the particles carried thereby so that a determination of the concentration of particles above and below the cutoff point can be obtained. Alternately, the major and minor flows and the particles can be passed through particle analyzer instruments for a direct particle measurement of each of the flows.

Abstract: An electrostatic precipitator assembly is disclosed. The assembly includes a tubular collector and an electrode suspended therein. The electrode includes a substantially cylindrical collector portion and a charging portion which includes a rod and a charging disk, wherein the gap between the charging disk and the collector is at least as great as the gap between the collector portion of the electrode and the collector.

Abstract: The present invention relates to a low particle loss cascade impactor with particle collection in externally removable cups for determining the size distribution of particles delivered form an aerosol atomizer. A plurality of downwardly facing cavities formed in the body are arranged from a first end to a second end of the body in a generally zig-zag pattern. Each cavity has a generally cylindrical inner wall surface defining an opening facing in a second direction and a surface facing in a first direction. An entrance passage extends from the outer surface of the body at the first end to a center region of a first cavity. The impaction stage is positioned such that a center line of the impaction stage intersects a center bisecting plane passing through the body at an included angle between about 10.degree. to 80.degree..

Abstract: A sampling inlet for sampling aerosols in atmospheric air comprises an inlet housing that has an air flow and an inertial particle classification device in a series flow path from an inlet opening in the sampler to a filter which collects the material. The sampler is a classification device of the virtual impactor type, utilizing nozzles that receive the flow carrying the aerosols, and a receiver tube that is aligned with the nozzle and spaced therefrom, with a major portion of flow being diverted from the space between the nozzle and the receiver tube. The heavier particles are carried by inertia into the receiver tube and then are carried off by minor flow of fluid that passes through the receiver tubes.

Abstract: A volumetric flow controller is used in connection with a virtual impactor classifier to control two separate flows in separate lines from an air pump. Each line has a flow control valve controlled in response to flow signals that are obtained from a pressure transducer that provides an electrical signal proportional to pressure. Pressure changes are sensed and the provided electrical signal is compared with a reference and will actuate a damper motor and move a flow control butterfly valve in the flow line for adjusting the flow when the pressure signal is different from the reference. The circuitry used provides for a dead band, so that changes in the butterfly valve setting will not occur unless the flow varies a selected amount, and also a timer control is used so that the motor operating the damper will be operated only at selected time intervals to prevent "hunting" or continuous operation of the valves. Further, temperature compensation signals can be provided as desired.

Abstract: A particle concentrating sampler utilizes a virtual impactor, which is an inertial classifier, for concentrating airborne particles above a cut size into a smaller volume air. The concentrated particles are counted, or collected on impactor plates or by using other collection techniques, such as filters or electrostatic precipitators. The concentration of the larger particles which are of interest for analysis insures that the number of particles, particularly in clean room environments, is sufficient so that a significant sampler or count can be obtained without sampling large volumes of air.

Abstract: A personal sampling impactor that comprises a compact mounting arrangement using a base, a cover, and an impactor plate cartridge that fits within the cover and is supported on an upper end of the base. A filter is held in place between the impact plate cartridge and the base, and the cover is made so that it can easily be placed over the impaction plate and latched in place to hold the unit together. The cover has inlets that align with a lightly oiled impaction plate surface on which particles will adhere.

Abstract: A compact air sampling impactor assembly has an inlet nozzle overlying an impaction plate that is mounted on a flat housing that defines an interior chamber covered by a filter. An air flow outlet tube leading from the chamber is connected to an air pump and a flow is established through the nozzle so the air impinges on the impaction plate to leave particles thereon and the flow then passes through the filter to the chamber and then out the air outlet. The size is kept small for personal use. Cascade impactors can be made using additional flow paths defining covers in association with the basic impactor plate and filter-carrying housing.

Abstract: A high volume virtual impactor for sampling atmospheric aerosols has a plurality of inlet nozzles and associated receiving tubes mounted in a common frame or housing having passageways which divide the airflow through the inlet nozzles into a major flow and a minor flow. The minor flow, or the smaller volume flow, passes through the respective receiving tube into a common chamber, while the major flow is caused to turn 180.degree. between flow exit of the inlet nozzle and its associated receiving tubes and pass as through a small particle filter. The impactors are arranged in oppositely facing and aligned pairs. The exhaust ends of the receiving tubes in a part face each other, so that the flows from the receiving tubes will intermix in the center of a chamber, to prevent substantial particle impingement against the housing surfaces. The filters are located at the bottom of the housing to minimize losses.

Abstract: An impactor apparatus operable to collect particles for subsequent gravimetric or chemical analysis. The apparatus has a first assembly for supporting particle impaction means and a second nozzle assembly releasably mounted on the first assembly having nozzle means for directing gas and particles to the particle impaction means. The nozzle assembly can be removed from the first assembly supporting the particle impaction means and reassembled after an impaction test on a new assembly having cleaned particle impaction means. A cover is mounted on the assembly so that the assembly, along with the particle impaction means, can be transported to the laboratory for analysis. A modification of the particle impactor apparatus has rotating table means aligned with a plurality of nozzles so that a uniform layer of particles are deposited on each of the impaction plates carried by the tables.

Abstract: A single stage impactor having a plurality of different sized nozzles that predicate a particle collection efficiency curve that approximates a predetermined curve. The impactor has a particle collection plate mounted on a casing having a passage connected to an air moving device. A nozzle plate having a plurality of different sized nozzles is mounted on the collection plate. The nozzles can be round, rectangular, or a combination of round and rectangular. The sizes of the different nozzles are coordinated with the pressure drop across the nozzle plate to provide the nozzles with different particle collection cut-off characteristics. The combined collection efficiency curve or penetration curve of all of the different sized nozzles approximates a predetermined curve, as a respirable particle penetration curve.

Abstract: A method and apparatus for generating dry dust particles of a constant concentration from dry solid particles. The apparatus has a dust dispersion section receiving powdered material from a dust feeding section. The dust dispersion section includes a bed of beads subjected to a constant supply of air. An endless chain delivers a continuous supply of powdered material to the bed of beads and the air moving through the bed of beads. The chain is scrubbed by the beads and the air whereby the particles of powdered material are dispersed and entrained in the moving air. The particles move through a tube and are electrically neutralized with a radioactive source. A particle separator can be used to remove large particles. A photometer monitors the concentration of the particles emanating from the apparatus in aerosol form.

Abstract: A precision aerosol divider used primarily as a calibration device for a mass monitor instrument. The divider is made up of a filter holder with an isokinetic probe in the center that is connected to the inlet of the monitoring instrument. This type of arrangement provides for a flow split by a fixed ratio of the incoming aerosol stream into the filter and mass monitor. A special filter clamping device minimizes the disturbance of the deposit thereon by preventing rotation of the filter. Two pins in a filter retaining ring located between two sections of the holder body act to provide this clamping function.