40+ Senior Instrument Engineer Interview Questions and Answers

In our plant, we have a wide range of instruments including pressure transmitters, temperature sensors, flow meters, level indicators, control valves, and analyzers.

• Pressure transmitters

• Temperature sensors

• Flow meters

• Level indicators

• Control valves

• Analyzers

The device which generates microwave in radar is called a magnetron.

• Magnetron is a type of vacuum tube that generates microwaves using the interaction of a stream of electrons with a magnetic field.

• It is commonly used in radar systems, microwave ovens, and other electronic devices that require high-frequency electromagnetic waves.

• Examples of radar systems that use magnetrons include weather radar, air traffic control radar, and military radar systems.

The holes in the metal pipe inside the tank for radar gauge are for pressure equalization.

• The holes allow the pressure inside the pipe to equalize with the pressure inside the tank.

• This prevents any false readings due to pressure differences.

• The number and size of the holes are designed based on the tank size and fluid properties.

• The holes also prevent any vacuum formation inside the tank during fluid withdrawal.

• Examples of tanks that use radar gauges with metal pipes and hol...read more

Control valve components, characteristics, and applications

• Control valve components include actuator, positioner, and valve body

• Characteristics include linear, equal percentage, and quick opening

• Linear valves are used for on/off applications, equal percentage for modulating flow, and quick opening for emergency shutdown

• Applications include oil and gas, chemical, and power generation industries

Commissioning of a sub sea PLEM to CRP #1500 class shut down valve instrumentation.

• Ensure proper installation of the valve and its associated instrumentation.

• Perform loop checks and functional tests to verify proper operation.

• Calibrate and configure the valve instrumentation according to the control system requirements.

• Verify the valve's response to control signals and emergency shutdown signals.

• Perform a final inspection and documentation of the commissioning process.

AI, AO, DI, DO signals are types of signals used in instrumentation engineering.

• AI stands for Analog Input and refers to signals that are continuous and can take any value within a range.

• AO stands for Analog Output and refers to signals that are continuous and can be controlled to produce a specific output value.

• DI stands for Digital Input and refers to signals that are discrete and can only take on two values, typically 0 or 1.

• DO stands for Digital Output and refers to signa...read more

Flashing and cavitation can cause damage and performance issues in control valves, affecting system efficiency and reliability.

• Flashing occurs when liquid turns to vapor due to pressure drop, leading to reduced flow and potential valve damage.

• Cavitation is the formation and collapse of vapor bubbles in a liquid, causing shock waves that can erode valve components.

• Both phenomena can lead to increased noise and vibration, impacting the longevity of the control valve.

• Example: In...read more

Soft tags are assigned in software while hard tags are assigned in hardware.

• Soft tags are used for variables that are not directly connected to hardware.

• Hard tags are used for variables that are directly connected to hardware.

• Soft tags can be assigned through the DCS software.

• Hard tags are assigned through the hardware configuration.

• Examples of soft tags include calculated values and setpoints.

• Examples of hard tags include temperature sensors and valve positions.

Mass flow meter measures the mass flow rate of a fluid in a pipeline.

• Mass flow meter works on the principle of Coriolis effect or thermal dispersion.

• It measures the mass flow rate of a fluid in a pipeline.

• The fluid flows through a vibrating tube and the frequency of vibration is proportional to the mass flow rate.

• It is commonly used in industries such as oil and gas, chemical, and food processing.

• It provides accurate and reliable measurement of fluid flow.

Drum level maintenance differs in 3-element and single element systems.

• In 3-element systems, the drum level is controlled by measuring the water level, steam flow, and feedwater flow.

• In single element systems, only the water level is measured.

• Maintenance in 3-element systems involves checking and calibrating the sensors for each parameter.

• Maintenance in single element systems involves checking and calibrating the water level sensor.

• Regular maintenance is necessary to ensure a...read more

I will ensure smooth start up for plant by conducting thorough testing, creating detailed procedures, and training the operators.

• Conduct thorough testing of all equipment and systems before start up

• Create detailed start up procedures and checklists

• Train operators on the procedures and ensure they understand their roles and responsibilities

• Perform simulations and drills to identify and address any potential issues

• Collaborate with other departments and stakeholders to ensure a ...read more

Last issue faced was with a pressure transmitter.

• The pressure transmitter was giving erratic readings.

• Checked the wiring and found a loose connection.

• Tightened the connection and calibrated the transmitter.

• Verified the readings and ensured proper functioning of the instrument.

Emerson transmitters are widely used in industrial instrumentation for measuring and transmitting process variables.

• Emerson transmitters are known for their accuracy, reliability, and advanced features.

• They come in various models, each designed for specific applications and process variables.

• Some popular Emerson transmitter models include Rosemount 3051, 3144, and 644.

• The model number indicates the type of transmitter, its capabilities, and the range of measurements it can ha...read more

Types of valves include gate, globe, ball, butterfly, and check valves. Load cells measure weight, RTDs measure temperature, PTs measure pressure, LTs measure liquid level, FTs measure fluid flow, and TTs measure temperature.

• Valves: gate, globe, ball, butterfly, check

• Load cells: measure weight

• RTDs: measure temperature

• PTs: measure pressure

• LTs: measure liquid level

• FTs: measure fluid flow

• TTs: measure temperature

Yes, I am open to relocating for the Senior Instrument Engineer position.

• I am willing to relocate for the right opportunity.

• I understand that this position may require me to move to a different location.

• I am flexible and adaptable to new environments.

• I have previous experience relocating for work.

• I am excited about the potential opportunities that come with relocation.

Steam drum level transmitter measures the level of water in the steam drum using differential pressure.

• Uses differential pressure to measure the level of water in the steam drum

• Consists of two pressure sensors, one at the bottom and one at the top of the drum

• The difference in pressure between the two sensors is proportional to the level of water in the drum

• Common types include capacitance, ultrasonic, and radar transmitters

Radar level gauge uses electromagnetic waves to measure the level of liquid or solid in a tank or vessel.

• Radar level gauge emits high-frequency electromagnetic waves towards the surface of the liquid or solid in the tank.

• The waves are reflected back to the gauge by the surface of the liquid or solid.

• The time taken for the waves to travel to the surface and back is measured and used to calculate the level of the liquid or solid.

• The gauge can be used for both continuous and poi...read more

Interlocks are safety mechanisms that prevent the turbine from operating under unsafe conditions.

• Interlocks are designed to prevent damage to the turbine and ensure safe operation.

• They can be mechanical, electrical, or software-based.

• Examples include overspeed protection, low oil pressure shutdown, and high exhaust temperature shutdown.

• Interlocks are critical components of turbine control systems and must be properly maintained and tested.

• They are often required by regulatory...read more

Standardizing maintenance procedures involves creating clear guidelines, documentation, and training for consistent and efficient maintenance practices.

• Develop a comprehensive maintenance manual outlining procedures for different equipment and systems

• Implement a system for tracking maintenance activities and scheduling regular inspections

• Provide training to maintenance staff on the standardized procedures and ensure they are followed consistently

• Regularly review and update th...read more

Boiler drum level control maintains the water level in a boiler drum for efficient steam generation and safety.

• Level Measurement: Utilizes devices like differential pressure transmitters or float switches to measure the water level in the drum.

• Control Systems: Employs PID controllers to adjust feedwater flow based on the measured drum level, ensuring stability.

• Safety Considerations: Proper level control prevents low water conditions that can lead to overheating and potential ...read more

A VFD gas analyzer system is a system that uses variable frequency drives to control the speed of the gas analyzer pump.

• VFD gas analyzer systems are commonly used in industrial settings to monitor and control gas emissions.

• The system uses a VFD to control the speed of the pump, which in turn controls the flow rate of the gas being analyzed.

• This allows for more accurate and precise measurements of gas concentrations.

• VFD gas analyzer systems can be used for a variety of gases, ...read more

A control valve is a device used to regulate the flow of a fluid in a process system. Loop checking is the process of verifying the functionality of control loops.

• Control valve is used to control the flow rate, pressure, temperature, or level of a fluid in a process system

• Loop checking involves verifying the communication and functionality of control loops in a system

• Loop checking is typically done during commissioning or maintenance of a system

• Examples of loop checking inclu...read more

Electromagnetic flowmeter measures fluid flow by inducing a magnetic field and measuring the voltage generated by the fluid's movement.

• Uses Faraday's law of electromagnetic induction

• Fluid must be conductive

• No moving parts

• Accurate and reliable

• Commonly used in water treatment, chemical, and food industries

Various instruments and their makes

• Pressure Transmitter - Rosemount, Yokogawa, Honeywell

• Flow Meter - Endress+Hauser, Siemens, Emerson

• Temperature Transmitter - ABB, Siemens, Yokogawa

• Level Transmitter - Vega, Magnetrol, Krohne

Control valve troubleshooting involves identifying and resolving issues with the valve's performance.

• Check for any leaks or blockages in the valve

• Inspect the valve's positioner and actuator for any faults

• Verify that the valve is receiving the correct signals from the control system

• Check the valve's calibration and adjust if necessary

• Perform a functional test to ensure proper operation

PLC and SCADA DC's installation and commissioning involve setting up and testing the control systems.

• PLC and SCADA systems are installed and configured to control industrial processes.

• DC's (Distributed Control Systems) are used to monitor and control multiple processes from a central location.

• Installation involves mounting hardware, wiring, and configuring software.

• Commissioning involves testing and verifying the system's functionality.

• Examples of industries that use PLC and ...read more

A pressure transmitter hook up diagram shows how to connect the transmitter to the process piping and control system.

• The transmitter should be installed at the point where pressure is to be measured.

• The process piping should be connected to the high and low pressure ports of the transmitter.

• The transmitter should be connected to the control system using appropriate wiring.

• Proper grounding and shielding techniques should be used to prevent electrical interference.

• The hook up d...read more