Abstract: A gas analyzer apparatus includes a device or platform for supporting a predetermined quantity of a reagent capable of reacting with a predetermined gas to cause a detectable change in a characteristic of the reagent, a reservoir adapted to retain the reagent, a dispenser for dispensing a controlled quantity of the reagent from the reservoir to a predetermined position on the device for supporting the predetermined quantity of the reagent, and a detector that detects the presence of the predetermined gas upon the predetermined gas and the controlled quantity of reagent reacting to cause a detectable change in a characteristic of the reagent detectable by the detector, the detector adapted to detect a change in the controlled quantity of the reagent by detecting the change in the characteristic through the predetermined quantity of the reagent.

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.

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.