David A Dikken

US Patent:

20050247105, Nov 10, 2005

Filed:

Feb 16, 2005

Appl. No.:

11/060080

Inventors:

David Dikken - Bloomington MN, US
Robert Nelson - Hastings MN, US
Lloyd Keleny - Champlin MN, US
Mike Kiester - Stillwater MN, US
Andrew Dahlgren - Chanhassen MN, US

International Classification:

G01N001/00

US Classification:

073028040, 073061720

Abstract:

A particulate filter particularly suited for analytical gravimetric weighing applications is disclosed. The particulate filter includes a polytetrafluoroethylene (PTFE) media supported by a ring and yields stable microgram and submicrogram weighing results. The support ring may be PTFE, metal foil, or another non-hygroscopic polymer such that the mass of the filter does not vary with changes in atmospheric moisture. The filter simplifies the discharge of electrostatic charge buildup such that when a conductive filter media is combined with a conductive ring device, the discharge may be accomplished by placing the filter on a grounded weighing pan or other surface. The particulate filter can simplify filter identification by including identification symbols imprinted on each side of the filter media. Due to the chemically inert qualities of its components, the particulate filter is particularly suited for extraction techniques used during the detection of polycyclic hydrocarbons as is conducted in emissions and ambient air testing.

US Patent:

20100218595, Sep 2, 2010

Filed:

Dec 23, 2009

Appl. No.:

12/646434

Inventors:

David A. Dikken - Bloomington MN, US
Robert O. Nelson - Hastings MN, US
Lloyd G. Keleny - Champlin MN, US
Mike Kiester - Stillwater MN, US
Andrew Dahlgren - Chanhassen MN, US

Assignee:

MEASUREMENT TECHONOLOGY LABORATORIES CORPORATION - Minneapolis MN

International Classification:

G01N 1/22

US Classification:

73 2804

Abstract:

A particulate filter particularly suited for analytical gravimetric weighing applications is disclosed. The particulate filter includes a polytetrafluoroethylene (PTFE) media supported by a ring and yields stable microgram and submicrogram weighing results. The support ring may be PTFE, metal foil, or another non-hygroscopic polymer such that the mass of the filter does not vary with changes in atmospheric moisture. The filter simplifies the discharge of electrostatic charge buildup such that when a conductive filter media is combined with a conductive ring device, the discharge may be accomplished by placing the filter on a grounded weighing pan or other surface. The particulate filter can simplify filter identification by including identification symbols imprinted on each side of the filter media. Due to the chemically inert qualities of its components, the particulate filter is particularly suited for extraction techniques used during the detection of polycyclic hydrocarbons as is conducted in emissions and ambient air testing.

US Patent:

20130125623, May 23, 2013

Filed:

Dec 17, 2012

Appl. No.:

13/717328

Inventors:

David A. Dikken - Bloomington MN, US

Assignee:

MEASUREMENT TECHNOLOGY LABORATORIES, LLC - Minneapolis MN

International Classification:

G01N 5/02

US Classification:

73 2804

Abstract:

A particulate filter particularly suited for analytical gravimetric weighing applications is disclosed. The particulate filter includes a polytetrafluoroethylene (PTFE) media supported by a ring and yields stable microgram and submicrogram weighing results. The support ring may be PTFE, metal foil, or another non-hygroscopic polymer such that the mass of the filter does not vary with changes in atmospheric moisture. The filter simplifies the discharge of electrostatic charge buildup such that when a conductive filter media is combined with a conductive ring device, the discharge may be accomplished by placing the filter on a grounded weighing pan or other surface. The particulate filter can simplify filter identification by including identification symbols imprinted on each side of the filter media. Due to the chemically inert qualities of its components, the particulate filter is particularly suited for extraction techniques used during the detection of polycyclic hydrocarbons as is conducted in emissions and ambient air testing.