"If only
we'd known about Scott!"
ay-Lussac and Biot had only the most primitive instruments — among them, a caged lark! — when making their balloon ascensions in 1804. How much more accurate their atmospheric gas analyses would have been with a GC equipped with a Scott gas delivery system. Heart of such system is the Scott Model 18 regulator. Trademarked "The Protector", this high purity two-stage device is designed specifically to maintain the integrity of your GC gas delivery system. It eliminates the danger of ghost peaks in a way that lesser regulators cannot.
Are you fully aware of the risk of spurious experimental results arising from outgassing regulators and tubing — from driers and purifiers that actually wet and contaminate? Scott has put together a package of information on GC gas delivery systems including actual chromatograms showing just what you can and cannot expect from regulators and molecular sieve traps. The data are enlightening. Request your personal copy of this invaluable information package, and a copy of the 210page Scott Specialty Gases Catalog. Both are free. They are indispensable reading for the careful investigator. Visit us at Booth 5158-5160 during ISA/84
Scott Specialty Gases Plumsteadville, PA · 215: 766-8861 San Bernardino, CA · 714: 887-2571 Houston, TX · 713: 747-2385 Troy, Ml · 313: 589-2950 68
only 15% of its effort in creating a Dipmeter system was AI {12). The re mainder was in the design and devel opment of the user interface. Expert systems are not a substitute for data processing. They represent an evolu tion from current programming prac tices, and they embody a different way of looking at information. Learning. There has been much written in the popular press about sys tems that can learn from experience and can upgrade their own perfor mance. The advent of practical sys tems of this type will not occur in the immediate future. There are a few university learning systems, but they operate on very small problems that are well understood, where there are a very small number of parameters, and where all answers are immediately known to be right or wrong. Many industrial engineering prob lems have no absolute answers; there are only good, better, and best an swers. Much of the needed data is sim ply unavailable at the time that the problem has to be solved, and the number of needed variables is both enormous and currently undefined. The potential benefits of expert sys tem technology are enormous, but there is a great amount of work that has to be done to realize these benefits in the integrated industrial environ ment. References (1) Winston, P. H.; Horn, B.K.P. "LISP"; Addison-Wesley: Reading, Mass., 1981. (2) Wong, C. M. et al. Rev. Sci. Inst. 1983, 54,996-1004. (3) Yost, R. Α.; Enke, C. G. J. Am. Chem. Soc. 1978,100,2274-75. (4) Wong, C. M. et al. IEEE Trans. Nucl. Sci. 1984, NS-31 (1), 805-10. (5) Wong, C. M.; Lanning, S. M. "Energy and Technology Review," (UCRL52000-84-2), 8-15, Lawrence Livermore National Laboratory: Livermore, Calif., 1984. (6) Tompkins, J. W. In "IBM Engineering and Scientific Study Conference Pro ceedings"; IBM: Poughkeepsie, N.Y., 1982. (7) Weiss, S. et al. In "Proceedings of the National Conference on Artificial Intelli gence"; William Kaufmann, Inc.: Los Altos, Calif., 1982. (8) Ennis, S. P. In "Proceedings of the Na tional Conference on Artificial Intelli gence"; William Kaufmann, Inc.: Los Altos, Calif., 1982. (9) Van Melle, W. et al. Heuristic Pro gramming Project Report HPP-81-16, Stanford University: Stanford, Calif., 1981. (10) Smith, R. C; Friedland, P. Heuristic Programming Project Memo HPP-80-28, Stanford University: Stanford, Calif., 1980. (11) Forgy, C. E. "OPS-5 User's Manual," CMU-CS-81-135, Department of Com puter Science, Carnegie-Mellon Univer sity: Pittsburgh, Pa., 1981. (12) Smith, R. C; Baker, J. D. In "Pro ceedings of the Eighth International Joint Conference on Artificial Intelli gence"; William Kaufmann, Inc.: Los Altos, Calif., 1983.
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1332 A • ANALYTICAL CHEMISTRY, VOL. 56, NO. 12, OCTOBER 1984
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