Tsi, Inc.

Robert Caldow

Hee-Siew Han

Jason Paul Johnson

James E Farnsworth

Sreenath Avula

Sean Morell

Susanne Vera Hering

Gregory Stephen Lewis

Frederick R Quant

Richard Remiarz

George John Chancellor

Daniel C Bjorkquist

Jacob Hackbarth Scheckman

Tyler Anderson

Kenneth Farmer

Kenneth Rudolph Farmer, Ii

Veryl L Denler

Nathaniel Rudolph Farmer

Steven William Kerrigan

Jacob Scheckman

Kenneth Rudolf Ii Farmer

Nathaniel Rudolf Farmer

The disclosed subject matter compensates or corrects for errors that otherwise would be present when a measurement is made on a condensation particle counting system with the only difference causing the errors being absolute pressure. The difference in absolute pressure may be due to, for example, a change in altitude in which the condensation particle counting system is located. Techniques and mechanisms are disclosed to compensate for changes in particle count, at a given particle diameter, for changes in sampled absolute pressure at which measurements are taken. Other methods and apparatuses are disclosed.

Condensation particle counter efficiency compensation for altitude

Various embodiments include composite wicks for ultra-low noise condensation particle counters (CPCs). In one embodiment, a composite wick includes a first porous material having a first pore density, with the first porous material further having a first surface and an opposing second surface. A second porous material is in fluid communication with the first porous material and has a first surface with an area substantially the same as an area of the first surface of the first porous material. The first surface of the second porous material is substantially in contact with the first surface of the first porous material. The second porous material has a pore density that is dissimilar the first pore density of the first material. The first material and the second material are configured to provide vapor from a liquid to a fluid-based particle counter. Other apparatuses are disclosed.

Composite wicks for low noise particle counting

The respirator fit monitor described herein can be worn continuously by users so as to provide an indication as to how well their masks are fitting during use, thereby providing quantitative, wearable fit testers available for continuous use in real-life situations. The monitor includes a low-cost optical particle sensor assembly and controller unit for performing mask fit tests by comparing particle concentrations inside and outside of the mask. The fit test monitor is low cost and wearable, capable of dual sampling, capable of fit factor ratios well above 100, is battery powered and provides near real time measurements with a means for indicating the fit of the mask. The system includes wired or wireless communications for data logging, analysis and display capabilities.

Wearable mask fit monitor

There is disclosed a field calibratable particle sensor solution in a low-cost, very compact form factor. This makes a low-cost sensor more accurate for low-concentration pollution measurements and decreases the cost of pollution measurement systems having a wide geographic coverage. In a related embodiment, the invention illustrates a method and system to remotely and automatically calibrate one or more of the low cost sensors disclosed herein as well as other commercially available sensors (such as optical particle counters, photometers etc.) against a reference instrument (such as a beta attenuation monitor) which may or may not be physically located in the same place as the individual sensors. The method may require minimum (or no) user interaction and the calibration period is adjustable periodically.

System and method of conducting particle monitoring using low cost particle sensors

Various embodiments include methods and systems for reducing false-particle counts in a water-based condensation particle counter (CPC). One embodiment of a method includes delivering water into multiple wicks used for transporting separate portions of an aerosol sample flow, with the wicks extending from a wick stand on a first end to a flow joiner on a second end, combining particles from the separate portions of the aerosol sample flow into a single aerosol stream within the flow joiner prior to transporting the combined aerosol sample stream into a particle detection chamber within the CPC, sensing an excess volume of water delivered to the wicks, collecting the excess volume of water in a collection reservoir, and after receiving a signal corresponding to the excess volume of water, draining the excess volume of water from the collection reservoir. Other methods, systems, and apparatuses are disclosed.

Condensation particle counter false count performance

Various embodiments include methods of reducing false-particle counts in a water-based condensation particle counter (CPC). One embodiment of a method includes delivering water into one or more wicks, sensing an excess volume of water delivered to the wicks, collecting the excess volume of water into a collection reservoir, and draining the excess volume of water from the collection reservoir. Other methods and apparatuses are disclosed.

A saturator block assembly that is adapted for use with a condensation particle counter is described. The saturator block assembly is comprised of a member that is at least partially formed from a porous material that is adapted to absorb a working fluid. The saturator block assembly also includes at least one open column formed through the porous member. The open column is parallel with a length of the member and is adapted to emit the working fluid in vapor form from the porous material. The saturator block assembly is further comprised of an outer surface, and is adapted to operate at low pressure or low pressure transient applications. A volume of the porous material is configured so as to reduce the amount of air capable of being trapped in the pores of the porous material during low pressure or low pressure transient applications.

Apparatus and method for improving particle count accuracy in low pressure applications

An improved nanoparticle sizing apparatus comprised of a unipolar charger operatively coupled to a radial differential mobility analyzer in combination with a condensation particle counter and powered by a power source such as a battery or solar cell, thereby providing a portable sizing device.

Instrument for sizing nanoparticles and a component therefor

A continuous flow condensation particle counter employs a working fluid to saturate a gas stream, and then condense onto particles carried in the gas stream as the stream is directed through a condenser and cooled below the supersaturation point. A porous saturation block is positioned beneath the condenser, and receives droplets of working fluid condensate and water as the droplets descend from the condenser by gravity. The saturation block is constructed of a hydrophobic material, whereby it allows the working fluid to pass through but retains water within a collection reservoir centered below the condenser. A vacuum pump and a periodically actuated solenoid valve are employed to introduce a partial vacuum to the reservoir and thereby evacuate accumulated water. The preferred working fluid is a perfluorinated hydrocarbon fluid that is substantially odorless, chemically inert and non-flammable. Water is immiscible in the working fluid, and thus readily separable.

Growing community of inventors

Roseville, MN, United States of America

Robert Caldow