Robt Stone (ME) LLC Electrical & Instrumentation Engineer Interview Questions and Answers

Instruments used in control and instrumentation include sensors, transmitters, controllers, and actuators.

• Sensors: devices that detect changes in physical properties and convert them into electrical signals (e.g. temperature sensors, pressure sensors)

• Transmitters: devices that send signals from sensors to controllers (e.g. signal transmitters)

• Controllers: devices that receive signals from sensors and transmitters to re...read more

PID loop is a control system feedback mechanism used in industrial processes to maintain desired setpoints.

• PID stands for Proportional, Integral, Derivative

• Proportional term responds to the current error

• Integral term corrects past errors

• Derivative term predicts future errors

• PID controller continuously calculates an error value as the difference between a desired setpoint and a measured process variable

• Example: PID loop...read more

Instrumentation equipment refers to devices used to measure, control, and monitor various parameters in industrial processes.

• Instruments like pressure gauges, flow meters, and temperature sensors are commonly used in instrumentation.

• Control valves and actuators are used to regulate the flow of fluids or gases.

• Programmable Logic Controllers (PLCs) are used for automation and control of processes.

• Analytical instruments l...read more

A PLC panel wiring diagram is a visual representation of the electrical connections and components in a programmable logic controller panel.

• A PLC panel wiring diagram shows the layout and connections of various components such as power supplies, input/output modules, relays, and sensors.

• It helps technicians understand how the electrical signals flow within the panel and how different devices are interconnected.

• The diag...read more

A control valve is a device used to regulate the flow of fluid or gas in a process system.

• Control valves are commonly used in industries such as oil and gas, chemical, and power plants.

• They can be operated manually or automatically through an electrical or pneumatic signal.

• Control valves consist of a valve body, actuator, and positioner.

• They can control variables such as flow rate, pressure, temperature, and level.

• Exam...read more

A transmitter is a device used in instrumentation to convert a physical measurement into an electrical signal.

• Transmitters are commonly used in industries such as oil and gas, chemical, and power plants.

• They are used to measure variables such as pressure, temperature, flow rate, level, and pH.

• Transmitters typically consist of a sensing element, signal conditioning circuitry, and an output signal.

• The sensing element det...read more

Flow meters are devices used to measure the flow rate of a fluid or gas.

• Flow meters are commonly used in industries such as oil and gas, water treatment, and manufacturing.

• They can measure flow rates in various units such as liters per minute, cubic meters per hour, or gallons per minute.

• Different types of flow meters include electromagnetic, ultrasonic, turbine, and differential pressure flow meters.

• Flow meters can be...read more