Patents by Inventor Mark A. Hartfield

Mark A. Hartfield has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20060279224
    Abstract: Apparatus and methods are disclosed for measuring cathode fall within a fluorescent lamp that contains an electrode and a gas. A level of cathode fall associated with the electrode may be identified based on an intensity and wavelength of radiation emitted by the gas.
    Type: Application
    Filed: August 21, 2006
    Publication date: December 14, 2006
    Inventors: John Waymouth, Robert Nachtrieb, Farheen Khan, Mark Hartfield, Mark Taipale, Renzo DeMeo, Russell MacAdam
  • Publication number: 20060279221
    Abstract: Apparatus and methods are disclosed for measuring cathode fall within a fluorescent lamp that contains an electrode and a gas. A level of cathode fall associated with the electrode may be identified based on an intensity and wavelength of radiation emitted by the gas.
    Type: Application
    Filed: August 21, 2006
    Publication date: December 14, 2006
    Inventors: John Waymouth, Robert Nachtrieb, Farheen Khan, Mark Hartfield, Mark Taipale, Renzo DeMeo, Russell MacAdam
  • Patent number: 7070738
    Abstract: An analyzer having a combustion furnace includes a gas flow stream including a combustion detector in the stream of byproducts of combustion and a variable volume ballast chamber for receiving byproducts of combustion and which has a movable piston which moves in response to the introduced combustion byproducts. Subsequently, an aliquot sample from the chamber is forced through detectors for elements being detected. The method of analysis incorporating the present invention includes filling a variable volume ballast chamber with byproducts of combustion until combustion completion has been detected and, subsequently, forcing at least an aliquot sample of the combustion byproducts from the variable volume ballast chamber into a flow path including detectors for the elements of interest.
    Type: Grant
    Filed: February 18, 2004
    Date of Patent: July 4, 2006
    Assignee: Leco Corporation
    Inventors: Joel C. Mitchell, John T. Hoss, Mark A. Hartfield
  • Publication number: 20060122795
    Abstract: Apparatus and methods for measuring cathode fall in fluorescent lamps are disclosed. Together with measurements of cathode temperature, such measurements of cathode fall may inform a determination of cathode heater voltage as a function of discharge current (i.e., a cathode-heating-profile) that avoids both sputtering and excess-evaporation.
    Type: Application
    Filed: January 19, 2006
    Publication date: June 8, 2006
    Inventors: John Waymouth, Robert Nachtrieb, Farheen Khan, Mark Hartfield, Mark Taipale, Renzo DeMeo, Russell MacAdam
  • Publication number: 20060119276
    Abstract: Apparatus and methods for measuring cathode fall in fluorescent lamps are disclosed. Together with measurements of cathode temperature, such measurements of cathode fall may inform a determination of cathode heater voltage as a function of discharge current (i.e., a cathode-heating-profile) that avoids both sputtering and excess-evaporation.
    Type: Application
    Filed: January 19, 2006
    Publication date: June 8, 2006
    Inventors: John Waymouth, Robert Nachtrieb, Farheen Khan, Mark Hartfield, Mark Taipale, Renzo DeMeo, Russell MacAdam
  • Publication number: 20060122797
    Abstract: Apparatus and methods for measuring cathode fall in fluorescent lamps are disclosed. Together with measurements of cathode temperature, such measurements of cathode fall may inform a determination of cathode heater voltage as a function of discharge current (i.e., a cathode-heating-profile) that avoids both sputtering and excess-evaporation.
    Type: Application
    Filed: January 19, 2006
    Publication date: June 8, 2006
    Inventors: John Waymouth, Robert Nachtrieb, Farheen Khan, Mark Hartfield, Mark Taipale, Renzo MeMeo, Russell MacAdam
  • Publication number: 20050280371
    Abstract: Apparatus and methods for measuring cathode fall in fluorescent lamps are disclosed. Together with measurements of cathode temperature, such measurements of cathode fall may inform a determination of cathode heater voltage as a function of discharge current (i.e., a cathode-heating-profile) that avoids both sputtering and excess-evaporation.
    Type: Application
    Filed: August 11, 2005
    Publication date: December 22, 2005
    Inventors: John Waymouth, Robert Nachtrieb, Farheen Khan, Mark Hartfield, Mark Taipale, Renzo DeMeo, Russell MacAdam
  • Publication number: 20050093462
    Abstract: Apparatus and methods are disclosed for measuring cathode fall within a fluorescent lamp that contains an electrode and a gas. A level of cathode fall associated with the electrode may be identified based on an intensity and wavelength of radiation emitted by the gas.
    Type: Application
    Filed: April 6, 2004
    Publication date: May 5, 2005
    Inventors: John Waymouth, Robert Nachtrieb, Farheen Khan, Mark Hartfield, Mark Taipale, Renzo DeMeo, Russell MacAdam
  • Publication number: 20050093456
    Abstract: Apparatus and methods for measuring cathode fall in fluorescent lamps are disclosed. Together with measurements of cathode temperature, such measurements of cathode fall may inform a determination of cathode heater voltage as a function of discharge current (i.e., a cathode-heating-profile) that avoids both sputtering and excess-evaporation.
    Type: Application
    Filed: April 6, 2004
    Publication date: May 5, 2005
    Inventors: John Waymouth, Robert Nachtrieb, Farheen Khan, Mark Hartfield, Mark Taipale, Renzo DeMeo, Russell MacAdam
  • Publication number: 20040171165
    Abstract: An analyzer having a combustion furnace includes a gas flow stream including a combustion detector in the stream of byproducts of combustion and a variable volume ballast chamber for receiving byproducts of combustion and which has a movable piston which moves in response to the introduced combustion byproducts. Subsequently, an aliquot sample from the chamber is forced through detectors for elements being detected. The method of analysis incorporating the present invention includes filling a variable volume ballast chamber with byproducts of combustion until combustion completion has been detected and, subsequently, forcing at least an aliquot sample of the combustion byproducts from the variable volume ballast chamber into a flow path including detectors for the elements of interest.
    Type: Application
    Filed: February 18, 2004
    Publication date: September 2, 2004
    Inventors: Joel C. Mitchell, John T. Hoss, Mark A. Hartfield