An Introduction to Electrical Instrumentation and Measurement Systems

An Introduction to Electrical Instrumentation and Measurement Systems

Scientific and technical instruments have been defined as devices used in observing, measuring, controlling, computing or communicating. Additionally the same source* states that: 'Instruments and instrument systems refine, extend or supplement human facilities and abilities to sense, perceive, communicate, remember, calculate or reason'. The principal concern of this book is to describe instruments and their attributes so that the magnitudes of, and variations in, electrical, mechanical, and other quantities may be monitored in an optimized manner for any measurement situation. Before describing any instruments in detail it is desirable to consider the questions that must be answered before making any measurement. 

(a) What is the most suitable method of performing the measurement? 

(b) How should the result be displayed? 

(c) What tolerance on the measured value is acceptable? 

(d) How will the presence of the instrument affect the signal? 

(e) How will the signal wave shape affect the instrument's performance? 

(f) Over what range of frequencies does the instrument perform correctly? 

(g) Will the result obtained be affected by external influences?