Instrumentation is defined as the art and science of measurement and control of process variables within a production or manufacturing area. The process variables used in industries are Level, Pressure, Temperature, Humidity, Flow, pH, Force, Speed etc. Control engineering or control systems engineering is the discipline that applies control theory to design systems with desired behaviors. Control engineers are responsible for the research, design, development and control devices/systems, typically in manufacturing facilities and plants. The practice uses sensors to measure the output performance of the device being controlled and those measurements can be used to give feedback to the input actuators that can make corrections toward desired performance.