Perth Instrumentation Course
Back Published on June 22, 2023

What are the basic concepts of industrial instrumentation?

Professional Electrical Instrumentation

In the process sector and in manufacturing facilities, industrial instrumentation is a basic discipline. Although it may not be as widely known as industrial automation, there are technicians and engineers who are specifically trained in this area.

Industrial instrumentation, in its simplest form, is a multidisciplinary field requiring expertise in electrical electronics, chemistry, mechanics, microcontrollers and microprocessors, software language, and process control. Additionally, things like the fundamentals of industrial protocols, network communications, pneumatics, and hydraulics.

Let’s now define what “instrumentation” means.

What is Instrumentation?

Instrumentation refers to the process of measuring, analysing, and controlling electrical and non-electric physical values using a collection of diverse interconnected electrical, measurement, and control equipment.

Process instruments are classified into several sorts which includes electrical instruments, electronic instruments and mechanical instruments.

Purpose of industrial instrumentation

“Industrial instrumentation” is described as the process of measuring and controlling different quantities in manufacturing processes utilising different instruments or industrial components.

Any quantity must first be measured in order to be controlled. Following the measurement of the desired quantity, the measured values are communicated manually or automatically for indication, computation, or control reasons.

The control signal that the CPU sends to the control devices during an automatic control operation can be used to control the quantity.

In actual use, the sensors gather data from several fields, including flow, pressure, displacement, vibrations, etc., and send it to the control systems that will regulate these variable quantities.

In the industrial setting, programmable logic controllers (PLC) or distributed control systems typically handle control (DCS).

How industrial instrumentation works?

Industrial instrumentation is regarded as a science of automated system measurement and control. This technology has many uses in both academic and industrial research as well as in daily life.

ranging from thermostats in homes, aero plane autopilots, power plants, oil and gas refineries, manufacturing of pharmaceuticals, etc.

As we’ve already discussed, measurement is the initial stage in using industrial instruments. It serves no purpose to attempt to manage a process parameter if we cannot measure it.

In the sector, this “something” often takes one of the following shapes:

  • Flowing fluid.
  • Fluid pressure.
  • Object’s temperature.
  • Quantity of liquid inside a container.
  • Chemical concentration.
  • The acceleration, displacement, vibration, or movement of the machine.
  • Electrical resistance, voltage, current, etc.

Typically, after measuring the quantity of interest, we send a signal corresponding to this quantity to a PLC/DCS system, where either manual (manual) or automated action is subsequently performed.

As a result, if the control operation is automated, the final control element sends a signal to the PLC/DCS.

In most cases, the control devices are a control valve or an electric motor. A physical system known as a “process” connects these instrumentation and control devices to the measurement equipment.

Characteristics of industrial instrumentation

The sensors, transducers or input devices, controllers, processors, transmitters, and actuators of industrial instrumentation provide the foundation for its properties in real-time applications (output devices).

To measure and control physical quantities like flow, level, pressure, temperature, and so on, input instrumentation is utilised.

Controlling elements including valves, regulators, switches, and relays are a part of output instrumentation. These are designed to provide remote or automatic control capabilities, controlling the desired output variable. They are regarded as final control mechanisms or components. Below is a description of the three key components of industrial instrumentation.

Main elements of industrial instrumentation

1) Sensors

In real-time control and instrumentation applications, a variety of sensors are utilised as input devices, however the following sensors are the most frequently employed:

  • Pressure sensor
  • Flow sensor
  • Temperature sensor
  • Level sensor
  • Speed sensor
  • Photoelectric sensor
  • Pressure gauge
  • Thermistor
  • Thermocouple
  • Position and displacement sensor, among others.

2) Controllers

Mechanical or electronic systems are typically used to implement controllers or valves. However, modern industrial controllers and systems are computer-based. Thus, it facilitates the implementation of sophisticated control algorithms.

PLC (Programmable Logic Controller), DCS (Distributed Control Systems), and SCADA (Supervisory Control and Data Acquisition system) are the three most common control systems used in industrial instrumentation.

3) Actuators

The actuator transforms an electrical signal into a powerful action that is used to operate a mechanism or a system based on the signal that is provided to it. Actuators are controlled by the output signal from controllers or control systems like DCS, SCADA, or PLC used in industrial instrumentation.

Typically, electrical current, fluid pressure, and pneumatic pressure are used to control actuators. This energy is then transformed into mechanical energy or power. Now, the different types of actuators are:

  • Hydraulic actuator
  • Pneumatic actuator
  • Electrical actuator
  • Mechanical actuator

Input devices including valves, motors, relays, contactors, emergency lights, etc. are controlled by these actuators.

What does an industrial instrumentation technician do?

The industrial instrumentation technician often has professional training in industrial engineering or electronic engineering.

They must possess a strong foundation in electricity and electronics as a result of their training. For instance, understanding how a vibration monitor functions while simultaneously being able to use measuring devices.

In a nutshell, they are responsible for the calibration and verification of sensors (pressure, temperature, humidity, tachometer, rotation, and speed), transmitters, and their detectors in manufacturing plant facilities (pressure, temperature, and humidity).

In addition to controls, they oversee device repairs, device replacement, and instrument commissioning. Before and during the production of the process, they also examine to see if the installation complies with current norms and laws.

In fact, they perform the inspection and repairs of measuring devices, sensors, and controllers in accordance with high standards established by the manufacturer or current regulations.

Instrumentation engineers and technicians can have a wide range of profiles.

An engineer can work in maintenance, where he will be responsible for overseeing the upkeep of the field instruments and the control system.

Moreover, the engineer can also work in design, in which case he would be in charge of programming the control system, monitoring the installation, calibrating the sensors, etc.

To produce more reliable, cost-effective, and efficient outputs, all real-time operations in the production plant must be properly controlled. As a result, some equipment—referred to as instrumentation—is used to measure physical quantities like temperature, pressure, etc.

Thus, automation and industrial instruments are required to control diverse industrial operations.