# US 11,305,138 B2 · In situ respirator fit testing > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,305,138 B2 - Document ID: US11305138B2 - Status: Granted - Kind: B2 - Application number: 17/290,216 - Filed: 2019-10-31 - Published: 2021-10-14 - Granted: 2022-04-19 - Earliest claimed: 2018-11-01 - Assignees: TSI Incorporated; Aerosol Dynamics Inc. - Applicants: TSI Incorporated; Aerosol Dynamics Inc. - Inventors: Daniel C. Bjorkquist; Arantzazu Eiguren Fernandez; Kenneth Farmer; Melissa Grose; Susanne Vera Hering; Gregory Stephen Lewis; Steven Russel Spielman; David Workman - Web page: https://patentgrep.com/patent/US11305138B2 ## CPC - A62B 27/00: Methods or devices for testing respiratory or breathing apparatus {for high altitudes}(apparatus for testing gastightness in general G01M) - G01N 33/0016: {by regulating a physical variable, e.g. pressure or temperature} - G01N 1/2273: {Atmospheric sampling} - G01N 15/065: {using condensation nuclei counters} - G01N 2001/2276: {Personal monitors} - G01N 2015/0046: {in gas, e.g. smoke} - A62B: DEVICES, APPARATUS OR METHODS FOR LIFE-SAVING (valves specially adapted for medical use A61M39/00; life-saving devices, apparatus or methods specially adapted for use in water B63C9/00; divers' equipment B63C11/00; specially adopted for use with aircraft, e.g. parachutes, ejector seats, {B64D17/00, B64D25/10}; rescue devices peculiar to mining E21F11/00) - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) ## Abstract A system includes a first and second condensation particle counter, each counter having an inlet port, a growth column, and an optical element for counting particles detected at the respective inlet ports. The counters are configured to include a wick in which the wick is wetted by water. A differential pressure sensor is coupled to the first inlet port and coupled to the second inlet port. The sensor is configured to provide a pressure signal. A processor is coupled to memory and configured to receive the first signal, the second signal, and the pressure signal and generate an output corresponding to a ratio of the first signal and the second signal and correlate the ratio with the pressure signal. A housing is configured to receive the first counter, the second counter, the differential pressure sensor, the processor, and the memory. ## Claims ### Claim 1 A system comprising: a first condensation particle counter having a first inlet port, a first growth column, and a first optical element for counting particles detected at the first inlet port, the first condensation particle counter configured to provide a first signal corresponding to the particles counted at the first inlet port; a second condensation particle counter having a second inlet port, a second growth column, and a second optical element for counting particles detected at the second inlet port, the second condensation particle counter configured to provide a second signal corresponding to the particles counted at the second inlet port; wherein the first condensation particle counter and the second condensation particle counter are configured to include a wick in which the wick is wetted by water; a differential pressure sensor coupled to the first inlet port and coupled to the second inlet port, the sensor configured to provide a pressure signal; a processor coupled to memory and configured to receive the first signal, the second signal, and the pressure signal and generate an output corresponding to a ratio of the first signal and the second signal and correlate the ratio with the pressure signal; and a housing configured to receive the first condensation particle counter and the second condensation particle counter, the differential pressure sensor, the processor, and the memory. ### Claim 2 (depends on 1) The system of claim 1 further including an accelerometer coupled to the housing, the accelerometer configured to provide an acceleration signal corresponding to sensed acceleration, and wherein the processor is configured to receive the acceleration signal. ### Claim 3 (depends on 2) The system of claim 2 wherein the accelerometer is sensitive to acceleration in three dimensions. ### Claim 4 (depends on 2) The system of claim 2 wherein the processor is configured to correlate the acceleration signal with the ratio. ### Claim 5 (depends on 1) The system of claim 1 wherein the wick includes materials selected from Nylon, high-density polyethylene resin (HDPE), low-density polyethylene resin (LDPE), polyethylene, stainless steel, sintered material, ceramic, polyvinylidene fluoride (PVDF), nitrocellulose, polytetrafluoroethylene (PTFE), or hydrophilic material. ### Claim 6 (depends on 1) The system of claim 1 further including a thermal unit coupled to both the first condensation particle counter and the second condensation particle counter. ### Claim 7 (depends on 1) The system of claim 1 in which the housing is devoid of a reservoir. ### Claim 8 (depends on 1) The system of claim 1 further including a wireless transceiver coupled to the processor. ### Claim 9 (depends on 1) The system of claim 1 further including a battery coupled to the processor and carried by the housing. ### Claim 10 (depends on 1) The system of claim 1 wherein the processor is configured to calculate a protection factor. ### Claim 11 (depends on 1) The system of claim 1 further including a display affixed to the housing and configured to depict the ration. ### Claim 12 (depends on 1) The system of claim 1 wherein the first inlet port is configured to couple with a first end of a first tube, the first tube having a second end coupled to a respiratory mask. ### Claim 13 (depends on 12) The system of claim 12 wherein the second inlet port is configured to couple with a first end of a second tube, the second tube having a second end terminating proximate the respiratory mask.