20+ Instrumentation Technician Interview Questions and Answers for Freshers

Types of control valves, pressure parameters, types of gauges, SCADA and PLC full forms.

• Types of control valves include globe, butterfly, ball, and diaphragm valves.

• Pressure parameters include gauge pressure, absolute pressure, and differential pressure.

• Types of gauges include pressure gauges, temperature gauges, and flow meters.

• SCADA stands for Supervisory Control and Data Acquisition.

• PLC stands for Programmable Logic Controller.

Magnetic flowmeters, also known as mag flowmeters, measure fluid flow by using Faraday's law of electromagnetic induction.

• Mag flowmeters work based on the principle of Faraday's law of electromagnetic induction.

• They consist of a pipe with a magnetic field and electrodes on the sides.

• When a conductive fluid flows through the pipe, it generates a voltage proportional to the flow rate.

• The electrodes measure this voltage and convert it into a flow rate reading.

• Mag flowmeters are ...read more

Pressure unit is a measurement of force per unit area exerted on a surface.

• Pressure unit measures the amount of force applied to a given area.

• It is commonly used in various fields such as physics, engineering, and meteorology.

• The SI unit for pressure is Pascal (Pa), which is equal to one Newton per square meter (N/m²).

• Other commonly used pressure units include pounds per square inch (psi), atmospheres (atm), and bar.

• For example, tire pressure is often measured in psi, while a...read more

Control valves are used to regulate the flow of fluids in a process system.

• Control valves can be classified into different types such as globe valves, butterfly valves, ball valves, and plug valves.

• The working principle of control valves involves the use of a valve body, actuator, and positioner.

• The valve body contains a flow passage that can be opened or closed to control the flow of fluid.

• The actuator is responsible for moving the valve stem to open or close the valve.

• The p...read more

Near miss is a potential accident that did not result in injury or damage, accident is an unplanned event that results in injury or damage, incident is any event that disrupts normal operations.

• Near miss is a close call where an accident almost happened but was avoided.

• Accident is an unplanned event that results in injury, damage, or loss.

• Incident is any event that disrupts normal operations, regardless of outcome.

• Examples: Near miss - Almost tripping over a loose cable, Acci...read more

RTD (Resistance Temperature Detector) works on the principle of change in electrical resistance with temperature.

• RTD measures temperature by sensing the change in electrical resistance of a metal wire or film.

• As the temperature increases, the resistance of the RTD also increases.

• The most common type of RTD is made of platinum (PT100) and has a resistance of 100 ohms at 0 degrees Celsius.

• RTDs are highly accurate and stable temperature sensors used in various industries such as...read more

To install a temperature transmitter, you need to properly mount the transmitter, connect the wiring, configure the settings, and test the transmitter.

• Mount the temperature transmitter in a suitable location near the temperature source.

• Connect the wiring according to the manufacturer's instructions, ensuring proper grounding.

• Configure the settings such as range, output signal, and calibration using the transmitter's display or software.

• Test the transmitter by comparing the di...read more

PID controller installation involves mounting the controller, connecting it to the process, and configuring the parameters for optimal control.

• Mount the PID controller in a suitable location near the process equipment.

• Connect the controller to the process using appropriate wiring and communication protocols.

• Configure the PID parameters such as proportional, integral, and derivative gains for desired control performance.

• Tune the PID controller by adjusting the parameters based...read more

A hazard is a potential source of harm or danger that could cause injury, damage, or loss.

• A hazard can be a physical condition, activity, or substance that has the potential to cause harm.

• Hazards can be classified into categories such as biological, chemical, physical, ergonomic, and psychosocial.

• Examples of hazards include slippery floors, toxic chemicals, loud noises, heavy lifting, and workplace stress.

• Identifying and mitigating hazards is important to ensure safety in the...read more

A risk is the potential of gaining or losing something of value. It involves uncertainty and the possibility of negative outcomes.

• Risk is inherent in any decision or action taken.

• It involves assessing the likelihood of an event occurring and the potential impact if it does.

• Examples include financial risks, safety risks, and health risks.

Safety is the practice of preventing accidents, injuries, and hazards in the workplace.

• Safety involves following proper procedures and protocols to minimize risks

• It includes using personal protective equipment (PPE) when necessary

• Regular maintenance and inspections of equipment and machinery are essential for safety

• Safety also involves proper training and communication among team members

• Examples: wearing a hard hat in a construction site, using lockout/tagout procedures when ...read more

An instrument is a device used to measure, record, or control a process or quantity.

• Instruments can be used in various industries such as manufacturing, healthcare, and research.

• Examples of instruments include thermometers, pressure gauges, flow meters, and pH meters.

• Instruments can be analog or digital, manual or automated, depending on the application.

A limit switch is a device that detects the presence or absence of an object, usually in industrial applications.

• Limit switches are commonly used in machinery to control the movement of mechanical parts.

• They can be used to stop a motor when a door is opened, or to signal when a container is full.

• Limit switches typically have a lever or button that is actuated by the object being detected.

• They are often used in conjunction with a control system to automate processes and ensure...read more

Calibration of pressure and temperature involves adjusting instruments to ensure accurate readings.

• Calibration involves comparing the readings of a device to a known standard and making adjustments if necessary.

• For pressure calibration, a pressure gauge is connected to a reference standard to check accuracy.

• Temperature calibration may involve using a temperature bath with known values to adjust a thermometer.

• Regular calibration ensures that instruments provide accurate and re...read more

Calibration of control valve involves adjusting the valve to ensure it opens and closes at the correct set points.

• Calibration involves adjusting the valve to open and close at specific set points

• Use a calibration tool to adjust the valve position based on input signals

• Verify the valve's response to input signals after calibration

• Document the calibration process for future reference

To wire a field instrument to a PLC, you need to connect the instrument's terminals to the appropriate input/output modules on the PLC.

• Identify the type of field instrument and its communication protocol (e.g. 4-20mA, HART)

• Select the appropriate input/output module on the PLC for the instrument

• Connect the instrument's terminals to the corresponding terminals on the PLC module

• Configure the PLC software to communicate with the field instrument

• Test the communication between the ...read more

The question is incomplete and lacks context. Please provide more information.

• Please specify which symbol is being referred to

• Provide context for the symbol, such as its use in a particular industry or application

• If possible, provide a visual reference or description of the symbol