||Improvement of Optical Efficiency of Luminescence of a Flame Photometric Detector.
||Baird-Atomic, Inc., Bedford, Mass.
||273-5401-FR; EPA-71-50; R2-73-193;
( Gas detectors ;
Sulfur dioxide) ;
Flame photometry ;
Performance evaluation ;
Air pollution detection
||Most EPA libraries have a fiche copy filed under the call number shown. Check with individual libraries about paper copy.
A project was initiated with principal objective being to increase the optical efficiency of the Melpar flame photometric detector for the detection of SO2. Two routes were explored. First, the spatial distribution of sulfur and background emissions were plotted to establish regions of greatest signal/background. Second, multi-slits were constructed to match the structured sulfur emission and allow background subtract. The spatial studies of sulfur and background emission demonstrated that the optimum signal/background is obtained below the geometric center of the standard burner. The distribution suggested use of a monochromator with horizontal entrance slit rather than a filter. A study of the line emission of sulfur demonstrated that multiple slits could be constructed which would both increase specificity for sulfur and increase the usable signal. Using multi-slits in the non-differential mode the final sensitivity was about an order of magnitude greater than the comparison standard instrument.