These are devices & instruments for controlling and measuring fluid or process variables such as Level, Pressure, Temperature, Humidity, Flow, pH, Force, Speed etc.
Instrumentation and control are interdisciplinary fields. They require knowledge of chemistry, mechanics, electricity and magnetism, electronics, microcontrollers and microprocessors, software languages, process control, and even more such as the principles of pneumatics and hydraulics and communications. Common products are transmitters, sensors, regulators, control valves, PID controllers, electropneumatic (I/P) transducers, solid state relays, low water cut-offs, liquid level controls, water feeders, flow switches,