→ Primary elements: They are in contact with the fluid: pressure gauges, thermometers, pressure transmitters, orifice plates, etc.
→ Transmitters: capture the process variable through a primary element and transmit it remotely using a digital or analog signal.
→ Local indicators: capture the process variable and display it on a scale in a visible way: manometers, rotameters, thermometers. They can be connected to a transmitter.
→ Switches: capture the process signal and, for a set value, act on a switch, moving from the rest to the activated state: pressure switches, thermostats, level switches, flow switches, etc.
→ Converters: they receive the signal from an instrument and change it to another type of signal: from pneumatic to electronic signal, etc.
→ Final control elements: they receive a signal from a controller and modifies the flow: control valves, frequency inverter, etc.