Thomas Lee Pottberg

8284398, Oct 9, 2012

Jun 24, 2010

12/822497

Richard K. DeFreez - Azalea OR, US
Michael A. Potter - Wilderville OR, US
Thomas L. Pottberg - Grants Pass OR, US

Met One Instruments, Inc. - Grants Pass OR

G01J 3/46

356338

A nephelometer for detecting the concentration of particulates in a sample aerosol is provided with a branched flow path with a sample aerosol input, a clean gas input and an output leading to an optical sensor unit. At least one of the inputs has periodic variable flow so that a concentration-modulated gas stream is supplied to the optical sensor unit. The detector output of the sensor unit is processed in synchrony with the concentration modulation to filter out DC components, such as 1/f noise and parasitic instrument noise.

20190033194, Jan 31, 2019

Jul 26, 2017

15/660684

- Grants Pass OR, US
Michael A. Potter - Wilderville OR, US
Thomas L. Pottberg - Grants Pass OR, US

Met One Instruments, Inc. - Grants Pass OR

G01N 15/06
G01N 15/14
G01N 21/31

An apparatus comprising one or more pairs of analyzers measures light absorbing particulates, including black, brown, and ultraviolet light absorbing organic aerosols, suspended in gaseous samples, such as air. One analyzer receives an ambient gas sample, while the other analyzer is coupled to a dilution inlet that mixes ambient gas with a proportion of clean gas, whereby the two received samples have different particulate concentrations. Filters with identical filter areas accumulate particulates as the respective samples flow through with equal flow rate and velocity. An optical source and detector for each filter measures a changing property (e.g. attenuation at one or more wavelengths) as particulates accumulate. A computer uses the differential particulate accumulation from the ambient and diluted samples to compensate for filter loading effects upon the measurement to provide an accurate indication of particulate concentration in the ambient sample.

20150089999, Apr 2, 2015

Sep 29, 2014

14/500539

- Grants Pass OR, US
Thomas L. Pottberg - Grants Pass OR, US

F04B 39/00
G01N 33/00
F04B 49/08

73 2803, 417312, 417 43

A pulsation and particle suppressing continuous air flow system for air sampling instruments, particularly particle counters. An air pump occupies a portion of a sealed vacuum housing, with the other portion of the housing forming a surge chamber used to damp surges as the air pump attempts to pump air towards an air outflow port through an outflow pipe. The unoccupied volume of the surge chamber dampens or dilutes the surges at an air inflow port of the housing that is associated with an air sampling instrument, such as a particle counter. The air outflow port is associated with a filter for trapping particles originating inside of the air pump and associated motor while the interior of the housing itself traps particles originating outside of the air pump and motor.