Titrimeter for Sulfur-Containing Gases Most viewers of TV have at one time or another been exposed to a commercial in which a. "mysterious marvelous machine" of science measures the odor of onion. A needle swings far in one direction, only to he returned to zero by the introduction of some material purported to cut dawn odors in the mouth and respiratory areas. Few viewers realiee that the instrument in use is a descendant of an mrly model developed by the Army Chemical Corps as a recording titrimeter to monitor the conoentretion of mustard gas in the atmosphere during tests of protective clothing. Dr. J. H. Northrup (Nobel Prize for Chemistry, 1947)developed the original device which involved a titration of mustard grts with bromine, the end point being determined potentiometrically. Dr. Philip A. Shaffer (NDRC) improved the design and increased the sensitivity down to0.1 ppm by providing for the generation of the bromine by electrolysis of XBr within the potentiometric cell. Further developments have been incorporated by Consolidated Engineering Carp. in the currently available "Titrilog." The bromine-generating current which is directly proportional to the amount of oxidieehle sulfur present in the sample is recorded on a strip chart. The value of this tool for peacetime industrial applications is one more illustration of Chemical Corps contributions to safeguarding life snd health. The automatic titrimeter is indispensable in smog studies and in all public health monitoring of atmospheres contaminated by H d , SOn, or other sulfur-containing gases. JEROMEGOLDENSON and CARLB. MAWWAND A m y Chenical Center Maryland
Volume 36, Number 3, March 1959
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