This book has been prepared keeping in view the abstractness of the science of process control and to help practising engineers, teachers and students of Instrumentation, Electrical and Electronics disciplines to understand this subject. The major topics of process control have been explained with greater lucidity through appropriate illustrative examples and a number of solved problems wherever required, for easier comprehension and quick assimilation of the subject. The subject matter has been carefully prepared to cater to the needs of multi-disciplined engineering students for whom process control systems are an integral part of their curriculum. It explains the concepts of process control instrumentation with a touch of practicality supported by a related mathematical background to make the reading journey interestingly instructive.