An In-Situ Monitor for HC1 and HF

A modified nondispersive infrared technique, Gas Filter Correlation (GFC), was demonstrated in the laboratory to provide a sensitive and specific means of measuring pollutant concentrations in the presence of interfering gases. The basic idea of GFC is that a pollutant gas matching the spectral characteristics of the pollutant to be detected can be used in a reference cell and thus provide high specificity. A theoretical analysis of the GFC technique is presented. Experimental results given demonstrate that the technique can be used to measure HC1 and HF concentrations of less than 0.1 ppm.