Monitoring CO -NDIR Method
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The document describes the EC9830 Gas Filter Correlation Carbon Monoxide (CO) Analyzer which uses NDIR (Non-Dispersive Infrared) technology to monitor CO levels in ambient air. It operates by measuring CO absorption of infrared radiation at specific wavelengths near 4.7 microns using an optical bench with a 5-meter folded path-length. The gas filter correlation wheel facilitates interference rejection while ensuring only CO-sensitive wavelengths are measured. Specifications include a range of 0-50 ppm or 200 ppm, resolution of 0.01 ppm, and precision of 0.1 ppm.
Monitoring CO -NDIR Method
- 1. Monitoring CO in Ambient Air Direct Reading NDIR Method
- 2. CO Methods of analysis Methods available to monitor CO in ambient air • IR Absorption • IR Absorption GFC • Open path spectrometry, ( IR DOAS)
- 3. EC9830 GFC CO Analyzer • Gas Filter Correlation Carbon Monoxide (CO) Analyzer • NDIR Gas Filter correlation technique The EC9830 analyzer 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 CO-sensitive IR wavelengths. • The CO content of the sample is continuously measured from a user-supplied air stream of which the instrument extracts 1 SLPM (standard liter per minute) of sample.
- 4. 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.
- 5. EC9830 Principle of Operation Sample Inlet Particulate Filter Absorption (Measurement Cell) IR Detector Microprocessor CO Output exhaust IR source Gas Filter Wheel
- 6. EC9830 GFC CO Analyzer Optical Bench with Multiple Path
- 7. EC9830 GFC CO Analyzer Analyzer Specifications • Range: 0 - 50 ppm to 200 ppm • Resolution: 0.01 ppm • Precision: 0.1 ppm • Lower detectable reading: 0.05 ppm • Noise: 0.025 ppm • Sample Flow Rate 1.0 slpm • Rise/Fall time, 95% of scale: Less than 40 seconds • Temperature range 5º to 40 º C