Infrared gas-filter correlation instrument for in situ measurement of gaseous pollutant concentrations.
An ir analyzer employing gas-filter correlation techniques has been designed and constructed to measure the concentrations of CO, NO, SO(2), HCl, and HF in the stacks or ducts of stationary pollutant sources. Use of a retroreflector allows the stack to be double passed, and no sample is extracted. For each gas, small interchangeable fixed-position grating polychromators are used as narrow (~1.5-cm(-1)) multiband spectral filters with the bands corresponding to locations of selected absorption lines. The approximate useful ranges (in parts per million-meters) over which this analyzer operates are 10-4000 for NO, 10-1500 for CO, 50-40,000 for SO(2), 10-2000 for HC1, and 5-200 for HF. The discrimination against other gases and particulates is excellent. The analyzer has been tested in the laboratory and on a variety of pollutant sources.
Herget
W F
WF
Jahnke
J A
JA
Burch
D E
DE
Gryvnak
D A
DA