Monitoring CO in Ambient AirDirect Reading NDIR Method

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ECRD Publications

CO Methods of analysisMethods available to monitor CO in ambient air IR Absorption IR Absorption GFC Open path spectrometry, ( IR DOAS)

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ECRD Publications

EC9830 GFC CO Analyzer Gas Filter Correlation Carbon Monoxide (CO) Analyzer NDIR Gas Filter correlation technique The EC9830analyzer operates by measuring CO absorption of IR radiation at highly specific wavelengths near 4.7 microns. The Analyzer uses an Optical Bench with a 5 meter folded path-length. The gas filter correlation wheel facilitates rejection of interference and the narrow band pass filter ensures measuring only the COsensitive IR wavelengths. The CO content of the sample is continuously measured from a user-supplied air stream of which the instrument extracts 1SLPM (standard liter per minute) of sample.

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ECRD Publications

EC9830 GFC CO Analyzer Operation While the instrument is operating, the filter wheel is continuously rotating. First, consider the difference in the detector signals between the CO and the N2 cells. signal passes CO cell,which is the reference signal. And the signal that passes the N2 cell which is the measurement signal this is composed of all wavelengths not absorbed by CO. The third signal is the dark current signal which is the signal without IR. The rotation of GFW creates the reference and measure phases. The reference and measure phase signal share the same source, detector, optical path; only the amount of CO in the sample cell can effect the difference in intensity between the two phases.C ECRD Publications

EC9830 Principle of OperationSample Inlet Particulate Filter Microprocessor CO Output

IR Detector IR source Gas Filter Wheel Absorption (Measurement Cell) exhaustECRD Publications

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EC9830 GFC CO Analyzer Optical Bench with Multiple Path

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ECRD Publications

EC9830 Operation

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ECRD Publications

EC9830 GFC CO AnalyzerAnalyzer Specifications Range: 0 - 50 ppm to 200 ppm

Resolution: Precision: Lower detectable reading: Noise: 0.025 Sample Flow Rate Rise/Fall time, 95% of scale: 40 seconds Temperature range

0.01 ppm 0.1 ppm 0.05 ppm ppm 1.0 slpm Less than 5 to 40 C

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ECRD Publications