Control & Instrumentation Engineer Interview Questions and Answers for Freshers

There are several types of water pumps used for different applications.

• Centrifugal pumps

• Submersible pumps

• Reciprocating pumps

• Diaphragm pumps

• Jet pumps

• Gear pumps

• Screw pumps

• Vane pumps

• Axial flow pumps

• Mixed flow pumps

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 in a temperature control system adjusts the heater output...read more

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 regulate processes (e.g. PID controllers)

• Actuators: devices ...read more

Transmitters convert physical signals into standardized output for measurement and control in various applications.

• 1. Pressure Transmitters: Measure pressure in liquids and gases (e.g., piezoresistive transmitters).

• 2. Temperature Transmitters: Convert temperature readings into standardized signals (e.g., RTD transmitters).

• 3. Level Transmitters: Measure the level of liquids or solids (e.g., ultrasonic level transmitters).

• 4. Flow Transmitters: Measure the flow rate of liquids o...read more

Analyzers are instruments used to measure and analyze physical or chemical properties in various applications.

• Gas analyzers: Measure the concentration of gases (e.g., CO2 analyzers).

• Liquid analyzers: Assess properties of liquids (e.g., pH meters).

• Spectrometers: Analyze light spectra to identify materials (e.g., UV-Vis spectrometers).

• Mass spectrometers: Determine mass-to-charge ratios of ions (e.g., used in chemical analysis).

• Chromatographs: Separate mixtures to analyze compon...read more