Instrumentation - Definition

Definition

The Oxford English Dictionary says (as its last definition of Instrumentation), "The design, construction, and provision of instruments for measurement, control, etc; the state of being equipped with or controlled by such instruments collectively." It notes that this use of the word originated in the U.S.A. in the early 20th century. More traditional uses of the word were associated with musical or surgical instruments. While the word is traditionally a noun, it is also used as an adjective (as instrumentation engineer, instrumentation amplifier and instrumentation system). Other dictionaries note that the word is most common in describing aeronautical, scientific or industrial instruments.

The utility of the word has somewhat decreased as sensors and control have become ubiquitous. A modern smart phone contains sensors and supporting electronics with all of the classical elements of an instrumentation system. An embedded accelerometer may determine the display orientation. The touch screen and digital camera are complex sensors. A common application is for the phone to read and interpret a 2-D bar code (matrix code, QR code) and to take action based on that interpretation.

Measurement instruments have three traditional classes of use:

• Monitoring of processes and operations
• Control of processes and operations
• Experimental engineering analysis

While these uses appear distinct, in practice they are less so. All measurements have the potential for decisions and control. A home owner may change a thermostat setting in response to a utility bill computed from meter readings.