Abstract: An improved apparatus and method for capturing and analyzing the end-tidal portion of an exhalation. The CO2 level of air drawn into the system (10) is monitored to distinguish inhalation and exhalation of breath. Upon detection of a decrease in the CO2 level in the air drawn into the system (10), indicating a transition between exhalation and inhalation a pair of flow selector valves (26, 28) are operated to capture the end-tidal volume of air drawn into the system (10) immediately prior to the detection of the decrease in the CO2 level. Incoming air is diverted around the captured volume of air, and the CO2 levels are continually monitored to ensure that the captured volume of air corresponds to the end-tidal portion of an exhalation. Once the captured volume of air is positively identified as the end-tidal portion of an exhalation, the captured volume is routed through a gas analyzer (44) for analysis of one or more predetermined gas levels.

Abstract: An improved apparatus and method for capturing and analyzing the end-tidal portion of an exhalation. The CO2 level of air drawn into the system (10) is monitored to distinguish inhalation and exhalation of breath. Upon detection of a decrease in the CO2 level in the air drawn into the system (10), indicating a transition between exhalation and inhalation a pair of flow selector valves (26, 28) are operated to capture the end-tidal volume of air drawn into the system (10) immediately prior to the detection of the decrease in the CO2 level. Incoming air is diverted around the captured volume of air, and the CO2 levels are continually monitored to ensure that the captured volume of air corresponds to the end-tidal portion of an exhalation. Once the captured volume of air is positively identified as the end-tidal portion of an exhalation, the captured volume is routed through a gas analyzer (44) for analysis of one or more predetermined gas levels.

Abstract: An improved apparatus and method for capturing and analyzing the end-tidal portion of an exhalation. The CO2 level of air drawn into the system (10) is monitored to distinguish inhalation and exhalation of breath. Upon detection of a decrease in the CO2 level in the air drawn into the system (10), indicating a transition between exhalation and inhalation a pair of flow selector valves (26, 28) are operated to capture the end-tidal volume of air drawn into the system (10) immediately prior to the detection of the decrease in the CO2 level. Incoming air is diverted around the captured volume of air, and the CO2 levels are continually monitored to ensure that the captured volume of air corresponds to the end-tidal portion of an exhalation. Once the captured volume of air is positively identified as the end-tidal portion of an exhalation, the captured volume is routed through a gas analyzer (44) for analysis of one or more predetermined gas levels.

Abstract: An improved apparatus and method for capturing and analyzing the end-tidal portion of an exhalation. The CO2 level of air drawn into the system (10) is monitored to distinguish inhalation and exhalation of breath. Upon detection of a decrease in the CO2 level in the air drawn into the system (10), indicating a transition between exhalation and inhalation a pair of flow selector valves (26, 28) are operated to capture the end-tidal volume of air drawn into the system (10) immediately prior to the detection of the decrease in the CO2 level. Incoming air is diverted around the captured volume of air, and the CO2 levels are continually monitored to ensure that the captured volume of air corresponds to the end-tidal portion of an exhalation. Once the captured volume of air is positively identified as the end-tidal portion of an exhalation, the captured volume is routed through a gas analyzer (44) for analysis of one or more predetermined gas levels.

Abstract: An improved apparatus and method for capturing and analyzing the end-tidal portion of an exhalation. The CO2 level of air drawn into the system (10) is monitored to distinguish inhalation and exhalation of breath. Upon detection of a decrease in the CO2 level in the air drawn into the system (10), indicating a transition between exhalation and inhalation a pair of flow selector valves (26, 28) are operated to capture the end-tidal volume of air drawn into the system (10) immediately prior to the detection of the decrease in the CO2 level. Incoming air is diverted around the captured volume of air, and the CO2 levels are continually monitored to ensure that the captured volume of air corresponds to the end-tidal portion of an exhalation. Once the captured volume of air is positively identified as the end-tidal portion of an exhalation, the captured volume is routed through a gas analyzer (44) for analysis of one or more predetermined gas levels.

Abstract: An improved apparatus and method for capturing and analyzing the end-tidal portion of an exhalation. The CO2 level of air drawn into the system (10) is monitored to distinguish inhalation and exhalation of breath. Upon detection of a decrease in the CO2 level in the air drawn into the system (10), indicating a transition between exhalation and inhalation a pair of flow selector valves (26, 28) are operated to capture the end-tidal volume of air drawn into the system (10) immediately prior to the detection of the decrease in the CO2 level. Incoming air is diverted around the captured volume of air, and the CO2 levels are continually monitored to ensure that the captured volume of air corresponds to the end-tidal portion of an exhalation. Once the captured volume of air is positively identified as the end-tidal portion of an exhalation, the captured volume is routed through a gas analyzer (44) for analysis of one or more predetermined gas levels.

Abstract: An improved apparatus and method for capturing and analyzing the end-tidal portion of an exhalation. The CO2 level of air drawn into the system (10) is monitored to distinguish inhalation and exhalation of breath. Upon detection of a decrease in the CO2 level in the air drawn into the system (10), indicating a transition between exhalation and inhalation a pair of flow selector valves (26, 28) are operated to capture the end-tidal volume of air drawn into the system (10) immediately prior to the detection of the decrease in the CO2 level. Incoming air is diverted around the captured volume of air, and the CO2 levels are continually monitored to ensure that the captured volume of air corresponds to the end-tidal portion of an exhalation. Once the captured volume of air is positively identified as the end-tidal portion of an exhalation, the captured volume is routed through a gas analyzer (44) for analysis of one or more predetermined gas levels.

Abstract: A non-dispersive infrared gas analyzer is disclosed that accurately measures the concentration levels of a plurality of gases within a gas mixture. The analyzer includes first and second sample cells and is utilized advantageously for the measurement of NO.sub.x and hydrocarbon gas present in the exhaust of an automobile engine. The gas mixture of the exhaust is chilled before entering the first sample cell to remove a substantial amount of the water vapor from that sample cell to facilitate measurement of the NO.sub.x gas. The second sample cell receives the gas mixtue in an unchilled state to allow for accurate measurement of the hydrocarbon gas. The analyzer includes processors which are utilized to further correct the NO.sub.x measurement and which also interact with each other to provide an output data stream that is representative of the concentration levels of the gases that are being analyzed.

Abstract: An improved gas analyzer for measuring the presence of one or more gaseous compounds in a gas sample. The gas analyzer has an infrared source stabilized against temperature variations by a radiation loading scheme in combination with a selected source environmental temperature sensitivity to provide a stable source temperature without a conventional temperature controller. A rotating interference filter assembly is disposed in the optical path. This assembly alternately totally blocks radiation, passes radiation in a wave length band which will not be absorbed by a random gas sample, and sequentially passes radiation in one or more additional bands which will be absorbed by one or more gases in the sample cell. The sample cell features a unique enclosed cell with infrared transparent windows which are substantially free of impingement of contaminants of the gas sample thereon. A unique detector provides protection against deterioration from moisture while allowing easy and inexpensive assembly.

Abstract: An improved gas analyzer for measuring the presence of one or more gaseous compounds in a gas sample. The gas analyzer has an infrared source stablized against temperature variations by a radiation loading scheme in combination with a selected source environmental temperature sensitivity to provide a stable source temperature without a conventional temperature controller. A rotating interference filter assembly is disposed in the optical path. This assembly alternately totally blocks radiation, passes radiation in a wave length band which will not be absorbed by a random gas sample, and sequentially passes radiation in one or more additional bands which will be absorbed by one or more gases in the sample cell. The sample cell features a unique enclosed cell with infrared transparent windows which are substantially free of impingement of contaminants of the gas sample thereon. A unique detector provides protection against deterioration from moisture while allowing easy and inexpensive assembly.

Abstract: An improved gas analyzer for measuring the presence of one or more gaseous compounds in a gas sample. The gas analyzer has an infrared source stabilized against temperature variations by a radiation loading scheme in combination with a selected source environmental temperature sensitivity to provide a stable source temperature without a conventional temperature controller. A rotating interference filter assembly is disposed in the optical path. This assembly alternately totally blocks radiation, passes radiation in a wave length band which will not be absorbed by a random gas sample, and sequentially passes radiation in one or more additional bands which will be absorbed by one or more gases in the sample cell. The sample cell features a unique enclosed cell with infrared transparent windows which are substantially free of impingement of contaminants of the gas sample thereon. A unique detector provides protection against deterioration from moisture while allowing easy and inexpensive assembly.