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 (11, 13) and is utilized advantageously for the measurement of NOx 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 (11) to remove a substantial amount of the water vapor from that sample cell (13) to facilitate measurement of the NOx gas. The second sample cell receives the gas mixture in an unchilled state to allow for accurate measurement of the hydrocarbon gas. The analyzer includes processors (37, 39) which are utilized to further correct the NOx 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:
The present invention pertains to a sidestream gas measurement system (80) that output signals emulating the signals output by a mainstream gas measurement system or portion thereof, so that the sidestream gas measurement system can seamlessly communicate with a host system configured to communicate only a mainstream gas measurement system or a portion thereof.
Abstract:
The present invention pertains to a sidestream gas measurement system (80) that output signals emulating the signals output by a mainstream gas measurement system or portion thereof, so that the sidestream gas measurement system can seamlessly communicate with a host system configured to communicate only a mainstream gas measurement system or a portion thereof.
Abstract:
분광계를 이용하여 샘플에서의 가스(15)의 농도 및/또는 가스(15)의 조성을 결정하는 방법은: 파장이 실질적으로 연속적으로 파장 범위를 통과하는 방사(19)를 전달하는 단계 -여기서, 파장 범위의 연속적인 통과는 파장 변조, 바람직하게는 실질적으로 조화 파장 변조에 의해 중첩됨- ; 상기 가스(15)에 의한 상기 방사(19)의 흡수로부터 흡수 신호(29)를 상기 방사(19)의 파장의 함수로 측정하는 단계(27); 상기 흡수 신호(29)를 제1 미분 신호로 변환하는 단계(31); 상기 제1 미분 신호(33)로부터 적어도 하나의 제1 측정 가스 농도 값(39)을 도출하는 단계(37); 상기 적어도 하나의 제1 측정 가스 농도 값(39)으로부터 상기 가스(15)의 농도 및/또는 조성(49)를 결정하는 단계(47)를 포함하고, 상기 파장 변조는 상기 가스(15)의 적어도 하나의 상태 변수의 변화에 대응하여 적응되며, 상기 방법은: 상기 흡수 신호(29)를 제2 미분 신호(35)로 변환하는 단계(31); 상기 제2 미분 신호(35)로부터 적어도 하나의 제2 측정 가스 농도 값(41)을 도출하는 단계(37)를 더 포함하는 것을 특징으로 하고, 상기 파장 변조는, 상기 제1 측정 가스 농도 값(39)과 상기 제2 측정 가스 농도 값(41)의 비(43)가 실질적으로 일정하게 유지되도록, 바람직하게는 연속적으로, 순응되는(45) 것을 특징으로 한다.
Abstract:
A method and system for correcting the effect of intensity fluctuations of the transmitted light in an absorption spectroscopy system used for the detection or measurement of chemical species in a medium, whereby one or more modulation bursts are imposed onto a light beam that passes through the medium. This burst signal may be obtained by modulating the bias current of a tunable diode laser, and the modulation burst signal may be optimally at the second harmonic of the modulation frequency of a wavelength modulated beam to allow usage of the same signal path processing used for the spectroscopic detection of the measurand for a second harmonic detection system. The burst signal can be controlled using a smooth window function to minimise the effects of non-linear perturbations that are inherent in tunable diode laser wavelength modulation spectroscopy systems, of optical interference fringes (etalons) and of the residual light absorption by background chemical species or the measurand at the wavelength coinciding with the modulation burst.
Abstract:
A method and apparatus for interfacing a plurality of volumetric measurement systems, each of which includes a gas measurement and a flow measurement system, to a host system via an interface unit.
Abstract:
A gas analyzer system includes an optical source, an optical filter assembly, a controller, and an analyzer. The optical source generates an optical signal. The optical filter assembly includes different optical filters in which to filter the optical signal. During operation, the controller selects sequential application of each of the different optical filters in a path of the optical signal to modulate the optical signal using different frequency bands of optical energy. The modulated optical signal passes through an unknown sample. The optical analyzer analyzes the modulated optical signal after passing through the sample to detect which types of multiple different gases are present in the sample.