Abstract: An apparatus and method for sampling and measuring air born particulate matter includes an inlet for the particulate containing gas to enter. A mechanism then removes coarse particles larger than a selected size while permitting filtered particles of less than the selected size to pass through. A chamber containing a quartz crystal sensor permits the filtered particles that have passed through to deposit to create an output signal in response to the deposited particle mass.

Abstract: An apparatus and method for sampling and measuring air born particulate matter includes an inlet for the particulate containing gas to enter. A mechanism then removes coarse particles larger than a selected size while permitting filtered particles of less than the selected size to pass through. A chamber containing a quartz crystal sensor permits the filtered particles that have passed through to deposit to create an output signal in response to the deposited particle mass.

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 cascade impactor apparatus has a series of vertically stacked impactor housing sections. Each of the impactor housing sections has an upper portion that supports a motor for driving an impactor plate that is positioned below a nozzle through which flow passes. Each housing section also has an outlet passageway leading to a lower impactor chamber for the next in a series of impactor chambers, except the last outlet passageway is coming through a filter to exhaust. The impactor chambers are defined by a skirt that seals on the neck of the next downstream housing section. The impactor plates are each driven by a separate motor, and held onto a hub on the motor output shaft with a magnetic coupling so the plates can be removed when the housings are separated.

Abstract: A cascade impactor apparatus has a series of vertically stacked impactor housing sections. Each of the impactor housing sections has an upper portion that supports a motor for driving an impactor plate that is positioned below a nozzle through which flow passes. Each housing section also has an outlet passageway leading to a lower impactor chamber for the next in a series of impactor chambers, except the last outlet passageway is coming through a filter to exhaust. The impactor chambers are defined by a skirt that seals on the neck of the next downstream housing section. The impactor plates are each driven by a separate motor, and held onto a hub on the motor output shaft with a magnetic coupling so the plates can be removed when the housings are separated.

Abstract: A compact cascade impactor is formed to classify particles carried in a flow through the impactor. The impactor has collection chambers that are arranged to conserve space and yet provide a large flow passageway. The collection chamber may be tear drop shaped and being nested together. The impactor includes nozzles that are used across a desired range without.

Abstract: A compact cascade impactor is formed to classify particles carried in a flow through the impactor. The impactor has collection chambers that are arranged to conserve space and yet provide a large flow passageway. The collection chamber may be tear drop shaped and being nested together.

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 pre-separator for separating out large particles from a fluid flow has a housing forming an interior chamber with an inlet and an outlet, and a separator plate in the chamber between the inlet and outlet. The separator plate has a surface facing the inlet that is provided with a liquid carrying tank into which the flow is directed when it enters the interior chamber through the inlet. The separator plate has a series of nozzle openings therethrough adjacent its periphery to the outside of the tank. The nozzle openings adjacent the periphery of the separator plate overlie a surface of the housing adjacent the outlet. The pre-separator thus has two impaction stages that permit use across a wide range of flows. The separator plate and the housing have surfaces which are tapered so that liquid in the housing can be drained out when the housing is inverted.

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: A orifice plate used in an impactor that has a large number of very small openings therein is made of a thin material, and has a plurality of projections that extend outwardly from one surface thereof. The orifice plate is mounted adjacent a plate surface, and the projections serve to support the orifice plate spaced from the surface when the orifice plate deflects under differential pressures.

Abstract: A mixer supports a cradle holding an inlet component for a cascade impactor, and has sealing caps to close open ends of the component to trap a solvent in the component. The cradle is rotated by a motor for dissolving particles in the inlet component.

Abstract: A compact cascade impactor is formed to classify particles carried in a flow through the impactor. The impactor has collection chambers that are arranged to conserve space and yet provide a large flow passageway. The collection chamber may be tear drop shaped and being nested together. The impactor includes nozzles that are used across a desired flow range without changing the nozzles.

Abstract: An aerosol impactor and monitor has a plurality of impactor stages, each of which will receive an aerosol and classify the aerosol according to particle size. The impactor stages have nozzle plates and impaction plates that reduce the effects of cross flow under high flow volumes, as well as including monitors for determining pressure drop to permit analyzation of performance of the impactors. The impaction plates are mounted so that they can be rotated within the separate impactor chambers through the use of magnetic attraction drives to eliminate the need for rotating seals and yet obtain the benefit of the rotatable impaction plates. Pressure sensors are used for determining pressure drop across nozzle plates, both to insure evaluation of the flow rate through the impactor and also to determine the condition of the nozzles.

Abstract: A method for automating the process of impaction of particles, recovering samples from a plurality of impaction cups, and washing the cups for a new cycle. The process includes steps of agitating the solvent used for dissolving samples, removing samples and transferring the samples to vials used in an analyzing instrument.

Abstract: A low volume vacuum source that utilizes a mechanical vacuum generating device. In particular, a syringe is used as a vacuum source and is connected through a check valve to a test fixture of a cascade impactor that is used for classifying particles. The test fixture has fluid passageways that seal onto the chambers of the compactor, and by pulling and retracting the syringe piston, the vacuum is generated in the test fixture. The vacuum level is measured with a gauge. A check valve in the syringe outlet line prevents bleed back of the vacuum once vacuum has been formed. A separate bleed valve can be opened for relieving the vacuum applied to the test fixture.

Abstract: A pre-separator for separating out large particles from a fluid flow has a housing forming an interior chamber with an inlet and an outlet, and a separator plate in the chamber between the inlet and outlet. The separator plate has a surface facing the inlet that is provided with a liquid carrying tank into which the flow is directed when it enters the interior chamber through the inlet. The separator plate has a series of nozzle openings therethrough adjacent its periphery to the outside of the tank. The nozzle openings adjacent the periphery of the separator plate overlie a surface of the housing adjacent the outlet. The pre-separator thus has two impaction stages that permit use across a wide range of flows. The separator plate and the housing have surfaces which are tapered so that liquid in the housing can be drained out when the housing is inverted.

Abstract: An induction port assembly that conforms to United States Pharmacopia Standards is formed of stainless steel, and is made in two sections that are welded together along a junction plane at a 45° angle to the axes of the tubular sections. The stainless steel induction port assembly is reduced in weight, by using thin wall sections, and includes coupling sections at the outer ends of the tubular portions. The coupling sections can be hardened on the outer surfaces that couple to other components. The interior surface of the tubular induction port assembly is polished after welding to the desired standards.

Abstract: A mixer supports a cradle holding an inlet component for a cascade impactor, and has sealing caps to close open ends of the component to trap a solvent in the component. The cradle is rotated by a motor for dissolving particles in the inlet component.

Abstract: A orifice plate used in an impactor that has a large number of very small openings therein is made of a thin material, and has a plurality of projections that extend outwardly from one surface thereof. The orifice plate is mounted adjacent a plate surface, and the projections serve to support the orifice plate spaced from the surface when the orifice plate deflects under differential pressures.