PREFACE TO THE THIRD EDITION
Fundamentals of Process Control Theory was written in 1981 as a prototype for ISAs Independent Learning Module publication series, and it rapidly became the best-selling book ever published by ISA. With the publication of the second edition in 1991, the strong popular acceptance continued and the book has approached "classic" status. This is especially satisfying for an author.
This textbook is designed for independent self-study. It is for the practicing engineer, first-line supervisor, or senior technician. College, university, and technical school students will also find the material appropriate. Fundamentals of Process Control Theory is designed to teach the basic principles or process automation and demonstrate how these principles are applied in modern industrial practice. Some knowledge of mathematics is necessary, of course, but I have made efforts to prevent the mathematics from being a barrier to study by those without strong math skills. The material is designed as an introductory or first-level course. A quick review into the specific topics covered.
This book is intended to be both theoretical and practical--that is, to show the basic concepts of process control theory and how these concepts are used in daily practice. This is a book about fundamentals, concepts, ideas, principles, theory, and behavior. It is not about hardware and software. To some extent, however, we all know that hardware and software will dictate what "theory" can be used and useful. Thus, the actual implementation of process control theory changes as hardware and software change, and this march of progress has made a third edition necessary. I hope this new edition proves useful to you, the student.
An effort has been made to make this presentation consistent with the various standards and practices used throughout the various worlds of process control and instrumentation. I have attempted to ensure that no significant inconsistency exists with the standards relating to terminology, especially Process Instrumentation Terminology, ANSI/ISA-S51.1-1979 (R 1993), and that is reflected in both the text and the Glossary given in Appendix B. Some minor inconsistencies may be noted wiht ANSI/ISA-S5.1-1984 (Reaffirmed 1992) Instrumentation Symbols and Identification (referenced and excerpted in Appendix A), in some of the figures of the presentation, but in no case have I found this to lead to confusion for students.
My special thanks goes to all who made the first and second editions of this book so successful. It is my hope that the revisions for the third edition, many of which were suggested by you, will make it even better.
Paul W. Murrill, July 1999
