Water Vapor Interference Correction in a Non Dispersive Infrared Multi-Gas Analyzer

We demonstrate an effective method to eliminate the interfering effect of water vapor in a non-dispersive infrared multi-gas analyzer. The response coefficients of water vapor at each filter channel are measured from the humidity of the ambient air. Based on the proposed method, the water vapor interference is corrected with the measured response coefficients. By deducting the absorbance of each filter channel related to water vapor, the measuring precision of the analyzer is improved significantly and the concentration retrieval correlation accuracy of each target gas is more than 99%.