What is instrumentation and controls?

Instruments and controls are essential components in various systems, particularly in engineering, manufacturing, aviation, and process industries. Instruments are devices used to measure physical quantities such as temperature, pressure, flow, or level, providing critical data for monitoring and analysis. Controls, on the other hand, are mechanisms or systems used to regulate processes based on the input from these instruments. Together, instruments and controls ensure that operations run efficiently, safely, and within specified parameters. Automation systems often integrate both, using sensors (instruments) to gather real-time data and controllers to make adjustments that maintain optimal performance.

What is instrumentation?

The tactic of using instruments is normally called instrumentation, but in industrial and manufacturing areas, the word stands for an extra meaningful view: the measurement of process variables (physical and electrical quantities like mass, temperature, pressure, capacitance, voltage etc.) and presenting them in useful form in order to control a system or process.

It's not unwise at all to call instrumentation the “ears and eyes” of the industry and manufacturing areas. Instrumentation is a branch of engineering that binds measurement and control together, providing insights into the current state of physical phenomena.

Necessity of instrumentation in modern industry

To predict any environment, it’s essential to study its overall state first. Precision and safety are important for the industrial sector. If the equipment is not under instrumentation, for example, it’s nothing but difficult to access the hazardous issues of that system if it is not under monitoring. Moreover, for precision and efficiency in manufacturing fields, instrumentation is crucial to uphold consistency and high productivity. In IOT (Internet of Things) and automated systems, instrumentation is a crying need.

Categories of Instrumentation Equipment:

Sensors/Transmitters: Temperature, pressure, flow, and level etc. are measured by them and they are primary data acquisition units.

Temperature Sensors: They sense the degree of heat of a system or environment.

Pressure Transmitters: Measure pressure, converting pressure into an electrical signal.

Ultrasonic/Radar Level Transmitters: They are devices that emit sound or radar waves and determine level by measuring the time of flight. They are non-contact.

pH Meters: These meters determine acidity or alkalinity.

Gas Analyzers: Evaluate specific gases in a mixture.

Conductivity Meters: Determine electrical conductivity of a solution.

What is control?

To achieve any predetermined objective, the maintenance and implementation of any system to maintain another system for proper operation is referred to as control. The control process follows a definite loop to achieve the goal. It is like the CPU of a computer or the brain of a human being.

Phenomena that a control loop involves:

• Taking measurement: Perform a recording of the measurement of phenomena to convert them to countable numbers.
•  Comparing values: Perform a comparison of the taken value to the previously designed value.
•  Making decisions: Analyzing the difference between the taken measurement and the predefined set-value.

What is the relationship between instrumentation and control?

“If you can’t measure it, you can’t control it!”

For the control of a system, instrumentation is a prerequisite. Instrumentation is the driving force to enable control. For ensuring signal integrity and data acquisition, instrumentation is required.

“Control utilizes instrumentation!”

Instrumentation gathers data and control processes it. Control processes variables by:

1 Decision making: Comparison between data is made and error or difference is determined.

2 Corrective action: Having identified the difference or error, actions are taken.

3  Actuation: The information is sent to physical working bodies such as motors, valves etc.

   Automation: Without employing manpower, the control system runs the system continuously.

Control Strategies:

Power generation, aerospace, HVAC systems, process industries like food and beverage, chemical, oil and gas etc. are driven by control. To manage and maintain industrial processes, the strategies are:

1.On/off Control: The simplest form of control, which renders the output either fully “on” or fully “off” (for example: light switch)

2. PID (Proportional-Integral-Derivative): P-controller renders output proportional to current state, I-controller eliminates steady-state error and D-controller helps to dampen oscillations.

3. DCS (Distributed Control System): Control is distributed by distributed control under centralized supervision.

4. SCADA (Supervisory Control and Data Acquisition): PLCs are located at remote locations and an infrastructure is built for communication. Central server supervises gathered data, monitor it and gives commands.

Variables measured by instrumentation and control engineering:

Temperature: The measurement of how hot or cold an environment is, which is the average kinetic energy contained by the particles of any substance.  The SI unit is Kelvin; it's measured in degrees Celsius (∘C), Fahrenheit (∘F) normally. From cooking to weather forecasting, the variable is under study.

Pressure: Force felt per unit area(Smaller the area, greater the force). Pascals (Pa), pounds per square inch (psi), bars (bar), and atmospheres (atm) are the measuring units. In fluid mechanics, hydraulic systems, meteorology etc are all blessed with the measurement of pressure.

Flow: The moving rate of fluid, indicating the volume or mass.  Gallons per minute (gpm), cubic feet per minute (cfm), liters per minute (L/min) and cubic meters per hour (m3/hr) are the measuring units. In chemical processing, water treatment, the measurement of flow plays a tremendous role.

P^H: Measurement of how acidic or alkaline a solution is. The concentration of hydrogen ions (H+) in a solution is determined, where the range is from 0 to 14. The greater the value, the more the solution is alkaline. A lower value indicates an acidic solution. However, P^H  =7 indicates a neutral solution. 

Speed: Changing position or rotational rate. No direction is indicated as speed is a scalar value. The units are: meters per second (m/s), kilometers per hour (km/h), miles per hour (mph), or revolutions per minute (rpm).

Force: A cause that transforms one state of matter to another or changes the current speed. A force can be a push or a pull. It's a vector quantity. The SI unit of force is the Newton (N). Pounds-force (lbf) and dynes (dyn) are other units.

Voltage: An electrical quantity related to current and power. It is the measure of potential difference, actually. Safe and efficient electrical systems need the study of voltage measurement.

Humidity: How much moisture an environment contains. Grams of water per cubic meter of air (g/m3) is used as a unit or humidity is measured in percentage. In weather and climate studies, industrial processes, and human comfort are evaluated by humidity.

Conductivity: The capacity to conduct electricity through a solution. Siemens per meter (S/m) is the SI unit for measuring conductivity. Industrial applications, chemical analysis are highly benefited by the phenomenon.

Moreover, process variables are too numerous in number and new ones are also discovered day by day.

What is I&C Engineering (Instrumentation and Control Engineering)?

In almost all sections, instrumentation and control is indispensable. Instrumentation and control engineering is the specialized discipline of engineering that offers optimum industrial output by manipulating various measured variables under supervision and analysis.

“Instrumentation and control are two sides of the same coin!”

As instrumentation and control are interdependent, the bonding of the two forms a distinct class of engineering called “Instrumentation and Control Engineering”. It enhances safety, processes optimization and efficiency, enables quality control and data, and utilizes data-driven machines. It offers a reduction in material waste and energy consumption. Operational cost is also minimized by instrumentation and control engineering, indeed.

Why is the role of I&C engineer important?

“A car is useless without a driver!”

Instrumentation and control engineering requires proper design-implementation-maintenance. To design the system designer is a must and engineers are nothing but “designers”. Instrumentation and control engineers utilize control algorithms and keep process parameters within strict tolerances.  

Targets of an instrumentation engineer

• Enabling automation
• Mitigating risks and enhancing safety
• Maintaining an optimum working environment for industries
• Processing data and forecasting future requirements.
• Making data-driven decisions.
• Meeting the standard of products in industrial fields.
• Innovating new trends to ensure the betterment of the industrial and manufacturing sector.

How can I&C engineering control our future industrial field?

The probable trends that can be made an epic and bring the potential into limelight glorifying industrial and manufacturing fields:

Industrial Internet of Things( IIoT): Utilization of smart sensors, cloud computing will be on high demand for time to time that are designed and implemented by instrumentation and control engineering. This enables remote monitoring and satisfying maintenance.

Artificial Intelligence (AI) and Machine Learning (ML): To make system more automated, these two are invaluable with their intellectual algorithms

Cybersecurity: To prevent or minimize malicious attacks and provide safety.

Sustainable and Green Technologies: I&C plays a vital role in the generation of energy efficiency solutions technologies for precise monitoring of systems.

Instrumentation and Control Engineering is a raw science that not only designs but also troubleshoots systems, shapes the future playing the role of driving force and enhances by redesigning. It unveils new strategies, new opportunities, and new dreams for countless industries.

Let’s go forward with I&C!