Instrumentation A new instrument designed €or ais pollution studies is sensitive t o 0.05 part per million of sulfur dioxide
ti@lealph MI, Bfiureeh forces are operating to make industrial concerns steadily more conscious of the necessity for avoiding atmospheric pollution. Examples of pollution such as the one that occurred a t Donora, Pa., in October 1948 as well as less severe but chronic pollution found in many highly industrialized areas, such as the Los Angeles area, have brought conditions forcibly to public attention. Stringent I a ~ sdesigmed to prevent objectionable afmospheria pollution have resulted. These necessitate means for investigating atmospheric pollution quantitatively. La\\-enforcement agencies must he able to determine when legally sperified contamination limits are being exceeded; industry must be in a position to know that it has not exceeded them. Spot checks bv manual chemical methods are not enough ; continuous iecords must be available. The problem of instrumentation to measure atmospheric pollution is not a simple one. Fiist, the amount of contamination permissible is Y e r y low-measured in parts per million: secondly, the nature of the contaminants is not al; and thirdly, it is not ~i-ayskiio~~-ii .~SY
Figure 1.
September 1951
easy to obtain representative Samples of the atmosphere. Sulfur dioxide is one of the more common contaminants introduced into the atmosphere by industrial operations. Ore treating and smeltinn operations, oil refining, and vatrioi'ptl instrument gives a continuous ineasiirement of the sulfur dioxidc concentratioii; it must be zeroed manually. For some purposes, it is desirahlt to have an instrumcwt that chec4
