The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 29, 2007
Filed:
Jan. 04, 2005
John A. Tiwet, Waukegan, IL (US);
Cary S. Stone, Prospect Heights, IL (US);
Richard A. Gorny, Des Plaines, IL (US);
John Chapples, Poole, GB;
Ian Robins, Dorchester, GB;
John A. Tiwet, Waukegan, IL (US);
Cary S. Stone, Prospect Heights, IL (US);
Richard A. Gorny, Des Plaines, IL (US);
John Chapples, Poole, GB;
Ian Robins, Dorchester, GB;
Honeywell Analytics, Ltd., Poole, Dorset, GB;
Abstract
A method and apparatus for gas detection uses a sensor such as an electrochemical (EC) cell and includes a feedback control loop to control a pump to establish a first predetermined gas flow rate to the EC cell. The concentration of the gas at the first predetermined flow rate is measured. If the detected concentration exceeds a predetermined Alert value at the first flow rate an Initial Warning without remedial action is generated, and, the system then changes the gas flow rate before an Alarm is indicated. An Alarm is signaled only if the system verifies the first measurement. Preferably the first flow rate is set to optimize the measurement accuracy of the EC cell being used, and the second flow rate is lower than the first. Verification of an Alarm at the first flow rate may be conducted quickly by a quick-reaction process. The controller may periodically cycle the flow rates between the first and second rates for better accuracy and faster verification times.