Process instrumentation.

In oil and gas industries, instrumentation is used to monitor and control the operating conditions of the facility, which helps to meet safety, environmental regulations, quality and productivity, profitable operation and stable plant operation objectives. It can be categorized under two main functions: 1) Input devices, which are measuring instruments that mainly look at the different process variables. 2) Output devices of the control system, which are called the final control elements. These act relative to the measured parameters to institute the required control action.

The input devices (instrumentation) measure four important operating parameters: pressure, temperature, flow and level. Advanced, online analyzers that measure process composition are also considered an element of process instrumentation.

The instrumentation consists of three main components:

1. A sensor, which is sometimes called a primary measuring element, to measure required physical properties
2. A transducer, which converts the sensor signal into a standard signal form that suits the control system such as a pneumatic signal (3-15 psi), an electric signal (4-20 mA), a digital signal of Foundation Fieldbus, etc.
3. A transmitter, which prepares the transducer signal for transmission without loss and then transmits it. Smart transmitters also send meaningful data about the status of the measuring instrument as a whole.

Process instrumentation includes the most common control element, the control valve, which consists of an actuator that converts the output signal from the control system into a signal that can allow the valve to respond, the positioner for adapting the response and the valve. Smart positioners can currently send and receive useful data to and from the control system for predictive maintenance purposes.