Biomedical Engineering Reference
In-Depth Information
Chapter 1
Measurement Technology
1.1 Introduction
Measurement is the act or the result of a quantitative comparison between a pre-
determined standard and an unknown magnitude. Scientific and engineering sensors
and instrument systems of a spectacular variety of size, weight, cost, complexity,
and technology are used in the modern industry. However, a close look would reveal
that all of them are composed of a set of typical functional elements connected in a
specified way to provide signal in a form necessary. Little progress is possible in any
field of investigations without the ability to measure. The progress of measurement
is in fact the progress of science and indirectly that of mankind.
I often say that when you can measure what you are speaking about, and express it in
numbers, you know something about it; but when you cannot measure it, when you cannot
express it in numbers, your knowledge is of a meager and unsatisfactory kind.
Lord Kelvin, Electrical Units of Measurement (1883)
Measurement is a vast field which embraces detection, acquisition, control, and
analysis of data. It involves the measurement of physical, electrical, mechanical,
optical, and chemical quantities and plays a very significant role in every branch of
scientific research and engineering process which include control systems, process
instrumentation, and data reduction. Measurement is generally specified as a
number followed by a unit. All measurements have three apparatus: the estimation,
an error bound, and a probability which the actual magnitude lies within the error
bound of the estimate [
1
].
1.2 Significance of Measurement
Measurement is a common string that runs through the fabric of all science and
engineering. Measurement is important link in the chain of events in research and
development. It begins with a definition of the problem and objectives, and ends
with the utilization of information.
