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methodology, and data analysis to meet the design objectives. Perhaps more than in any other
technical field, the approach taken in measurement design and the outcome achieved will often
depend on the attention and experience of the designer.
Upon completion of this chapter, the reader will be able to
identify the major components of a general measurement system, and state the function of
each,
develop an experimental test plan,
distinguish between random and systematic errors,
describe and define the various error types,
define a standard and distinguish among primary, secondary, and transfer standards, and
clearly delineate defined and derived dimensions in various unit systems.
1.2 GENERAL MEASUREMENT SYSTEM
A measurement
1 is an act of assigning a specific value to a physical variable. That physical variable
is the measured variable. A measurement system is a tool used for quantifying the measured
variable. As such, a measurement system is used to extend the abilities of the human senses that,
while they can detect and recognize different degrees of roughness, length, sound, color, and smell,
are limited and relative; they are not very adept at assigning specific values to sensed variables.
A system is composed of components that work together to accomplish a specific objective. We
begin by describing the components that make up a measurement system, using specific examples.
Then we will generalize to a model of the generic measurement system.
Figure 1.1 Common devices that
involve measurements.
1 There are many new engineering measurement terms introduced. A glossary of the italicized terms is located in the back of
the text for your reference.
2 Chapter 1 Basic Concepts of Measurement Methods
15:40:34 Page 2
methodology, and data analysis to meet the design objectives. Perhaps more than in any other
technical field, the approach taken in measurement design and the outcome achieved will often
depend on the attention and experience of the designer.
Upon completion of this chapter, the reader will be able to
identify the major components of a general measurement system, and state the function of
each,
develop an experimental test plan,
distinguish between random and systematic errors,
describe and define the various error types,
define a standard and distinguish among primary, secondary, and transfer standards, and
clearly delineate defined and derived dimensions in various unit systems.
1.2 GENERAL MEASUREMENT SYSTEM
A measurement
1 is an act of assigning a specific value to a physical variable. That physical variable
is the measured variable. A measurement system is a tool used for quantifying the measured
variable. As such, a measurement system is used to extend the abilities of the human senses that,
while they can detect and recognize different degrees of roughness, length, sound, color, and smell,
are limited and relative; they are not very adept at assigning specific values to sensed variables.
A system is composed of components that work together to accomplish a specific objective. We
begin by describing the components that make up a measurement system, using specific examples.
Then we will generalize to a model of the generic measurement system.
Figure 1.1 Common devices that
involve measurements.
1 There are many new engineering measurement terms introduced. A glossary of the italicized terms is located in the back of
the text for your reference.
2 Chapter 1 Basic Concepts of Measurement Methods