As it applies to industrial plants, instrumentation is the collection of devices and programming that control and measure industrial processes. In other words, instrumentation encompasses the automation of the physical plant operation and the measurement of levels, flow, position, pressure, temperature and velocity of all of the elements of the plant.

An instrument is a device that measures or controls flow, temperature, level, or pressure. The control systems that receive, analysis and send control signals to theses instruments are also considered as instrumentation. Control systems are devices such as; Batch Controllers, Distributed Control Systems (DCS),Flow Computers, PID Controllers, Process Logic Controllers (PLC's), and Single Loop Controllers.

Instrumentation is essential in the safe and efficient operation of an industrial plant.