Instrument Technology

Instrument Technology, Volume 1 focuses on the instruments used in the measurement, recording, and control of critical variables in industrial processes. More specifically, measurements of pressure, liquid level in a tank or vessel, flow, and temperature are discussed. Instruments are classified according to the physical principle upon which they are based. The discussion begins by introducing the reader to the system of units of measurement used throughout the text. This topic is followed by four chapters, each dealing largely with the mathematics and physics of the instruments, which are classified according to the decimal system. The first chapter describes the principles on which the measurement of pressure and the transmission of force by a fluid depend. Before considering the actual methods of measuring pressure, the book first explains the difference between absolute and differential pressure. The second chapter discusses how the level of liquid in a tank or vessel is measured using direct methods and pressure-operated types. The third chapter focuses on the measurement of flow using quantity meters and rate-of-flow meters. The final chapter is concerned with temperatures measured on different thermometers and the two fixed points used to compare such measurements: the lower fixed point (ice-point) and the upper fixed point (steam-point). This book is intended for instrument and chemical engineers, as well as for students studying both craftsmen and technician courses.