Title:
GAS MONITOR USING ELECTROCHEMICAL CELL AND METOD OF OPERATING
Document Type and Number:
WIPO Patent Application WO/2005/108953
Kind Code:
A2
Abstract:
A method and apparatus for gas detection (2) uses a sensor (7)such as an electrochemical (EC) cell and includes a feedback control loop to control a pump (6) 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.
Inventors:
TIWET JOHN A (US)
STONE CARY S (US)
GORNY RICHARD A (US)
CHAPPLES JOHN (GB)
ROBBINS IAN (GB)
STONE CARY S (US)
GORNY RICHARD A (US)
CHAPPLES JOHN (GB)
ROBBINS IAN (GB)
Application Number:
PCT/US2005/014753
Publication Date:
November 17, 2005
Filing Date:
April 28, 2005
Export Citation:
Assignee:
ZELWEGER ANALYTICS INC (GB)
TIWET JOHN A (US)
STONE CARY S (US)
GORNY RICHARD A (US)
CHAPPLES JOHN (GB)
ROBBINS IAN (GB)
TIWET JOHN A (US)
STONE CARY S (US)
GORNY RICHARD A (US)
CHAPPLES JOHN (GB)
ROBBINS IAN (GB)
International Classes:
G01N7/00; G01N33/00; (IPC1-7): G01N7/00
Foreign References:
| US5722449A | 1998-03-03 | |||
| US6076523A | 2000-06-20 |
Other References:
None
See also references of EP 1741076A4
See also references of EP 1741076A4
Attorney, Agent or Firm:
Vargo, Paul M. (120 S. Riverside Plaza - 22nd Flr, Chicago IL, US)
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