Liquid leakage detection system
Light guide for liquid detection and cable comprising such a guide
Optical fibre reflective diffraction grating devices
Method of producing fiber optic chemical sensors incorporating photocrosslinked polymer gels
Fiber optic chemical sensors based on polymer swelling
Cigarette package Patent #: 5379889
ApplicationNo. 811692 filed on 03/05/1997
US Classes:250/229, Light valve (e.g., iris diaphragm)356/437Gas
ExaminersPrimary: Westin, Edward P.
Assistant: Pyo, Kevin
Attorney, Agent or Firm
International ClassesH01J 005/16
AbstractA chemical sensor (11) including a light source (12) for producing a light flux bundle (16), an optical detector (14) for receiving a transmitted light flux bundle (24), and an absorber/expander sensor element (18) supported by a holder or support (20). Absorber/expander sensor element (18) is positioned in the space between light source (12) and optical detector (14). The absorber/expander material of sensor element (18) changes its size by either expanding or contracting in the presence of a particular chemical component. An edge (22) of sensor element (18) acts like a shutter and moves in and out of the path of travel of light flux (16), as the sensor element changes in size, which affects the intensity of light reaching and detected by optical detector (14). A method of detecting changes in the amount of a chemical analyte comprising the steps of transmitting a light flux (16) from a light source (12) past an absorber/expander (18) having a movable edge (22), exposing the absorber/expander (18) to the chemical analyte, and sensing the change in transmitted light flux (24) reaching the optical detector (14).