Patents by Inventor Alexander N. Wilis

Alexander N. Wilis 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).

  • Method and device for detecting reducing gas using semiconductor gas sensor
    Patent number: 5223783
    Abstract: A method and a device which uses a semiconductor type of sensor for detecting and measuring gas of the type such as hydrogen sulfide which depletes the oxygen component from the semiconductor sensor when exposed to the gas and thus lowers electrical resistance through the sensor which uses a pair of semiconductor gas detecting sensors. In one embodiment, the gas sensors are alternatively fed with gas to be sampled and air. In another embodiment, the gas sensors are alternatively turned on and off at predetermined intervals to replenish the depleted oxygen when the sensor is turned off and to sample when the sensor is turned on.
    Type: Grant
    Filed: May 1, 1992
    Date of Patent: June 29, 1993
    Assignee: Willis Technologies International, Inc.
    Inventor: Alexander N. Wilis