Patents by Inventor Alan E. Holme

Alan E. Holme 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).

  • Mass spectrometer with means to correct for threshold carbon dioxide
    Patent number: 4810877
    Abstract: A mass spectrometer adapted to monitor respiratory gases includes a spectrometer chamber arranged selectively to receive respiratory gas or an oxygen containing gas substantially free of carbon dioxide, together with means for correcting the detected level of carbon dioxide during respiration by that threshold level detected during the period when the mass spectrometer is responsive only to the oxygen containing gas.
    Type: Grant
    Filed: October 10, 1986
    Date of Patent: March 7, 1989
    Assignee: The BOC Group, Inc.
    Inventor: Alan E. Holme
  • Leak detectors
    Patent number: 4776207
    Abstract: Apparatus for leak testing an article by detecting with a vacuum detector the leakage of search gas through the article, the apparatus including a pumping system predominantly for evacuating the article under test together with an auxiliary pumping system for evacuating a search gas detector responsible to the search gas leaking through the article.
    Type: Grant
    Filed: May 7, 1987
    Date of Patent: October 11, 1988
    Assignee: The BOC Group plc
    Inventor: Alan E. Holme
  • Gas pressure measuring circuit
    Patent number: 4541286
    Abstract: In a circuit for controlling the temperature of a filament in a Pirani gauge head, secondary temperature compensation is provided by mounting an auxiliary resistor adjacent the temperature-compensating arm of a bridge. The auxiliary resistor forms part of a potential divider which provides a preset offset voltage to an associated output amplifier. This offset voltage is added algebraically to the variable voltage driving the bridge circuit so as to provide additional temperature compensation.
    Type: Grant
    Filed: August 24, 1982
    Date of Patent: September 17, 1985
    Inventor: Alan E. Holme