Patents by Inventor Christopher R. Sweet

Christopher R. Sweet 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).

  • Gas analyzer
    Patent number: 5488227
    Abstract: A gas analyser and detector has an infra red source, a gas chamber and a detector cell; the detector cell has a gas sample inlet, inlet and exit paths for an infra red beam and reflector means in the chamber comprising a convex surface and a concave surface. The reflector means ensures a long path length for the beam whilst reducing beam divergence and signal loss.
    Type: Grant
    Filed: October 11, 1994
    Date of Patent: January 30, 1996
    Assignee: Geotechnical Instruments (UK) Limited
    Inventor: Christopher R. Sweet
  • Method and apparatus for measuring liquid level in the ground
    Patent number: 5027655
    Abstract: A method of detecting water level in an elongate cavity comprises emitting an alternating signal into the cavity, varying the frequency of said signal to provide a specific response from the cavity, detecting said response, and comparing said outgoing signal and response. In a preferred embodiment the response is a returning signal reflected from the surface of the water. The frequency of the outgoing signal may be varied continuously to establish a substantially steady state difference frequency between the outgoing and returning signal.
    Type: Grant
    Filed: October 3, 1989
    Date of Patent: July 2, 1991
    Assignee: Geotechnical Instruments (UK) Limited
    Inventor: Christopher R. Sweet