Question 1

Pneumatic control system

Accepted Answer

A control system using compressed air as the medium for transmitting control signals.

Question 2

Programmable logic controller (PLC)

Accepted Answer

A digital electronic device that uses programmable memory to store instructions and perform specific functions for controlling machines and processes.

Question 3

Loop tuning

Accepted Answer

The process of adjusting controller parameters to achieve optimal process control.

Question 4

Hysteresis

Accepted Answer

The lag in response exhibited by a system when its controlling parameters change, such as a change in direction or temperature.

Question 5

Deadband

Accepted Answer

The range of input values within which no change in output occurs.

Question 6

Control valve

Accepted Answer

A device used to regulate the flow of a fluid, such as a gas or liquid, in response to a control signal.

Question 7

Transducer

Accepted Answer

A device that converts one form of energy, such as mechanical or thermal, into another form, such as electrical.

Question 8

Distributed control system (DCS)

Accepted Answer

A control system in which the controllers are distributed throughout the plant, typically using digital communication networks.

Question 9

Proportional-integral-derivative (PID) controller

Accepted Answer

A feedback controller that uses a combination of proportional, integral, and derivative actions to control a process.

Question 10

Cascade control

Accepted Answer

A control strategy that uses multiple feedback loops to improve overall control performance.

Question 11

Sensor

Accepted Answer

A device that detects and responds to changes in a physical or environmental variable, such as temperature, pressure, or flow rate.

Question 12

Actuator

Accepted Answer

A device that converts a control signal into mechanical motion or another form of energy to affect the process being controlled.

Question 13

Calibration

Accepted Answer

The process of adjusting an instrument to provide accurate readings within a specified range.

Question 14

Zero drift

Accepted Answer

The change in an instrument's output when the input remains constant over time.

Question 15

Span

Accepted Answer

The difference between the upper and lower limits of an instrument's measurement or control range.

Question 16

Gain

Accepted Answer

The ratio of output to input in a control system.

Question 17

Time constant

Accepted Answer

A measure of the time it takes for a system's response to reach a specific percentage of its final value following a step change in input.

Question 18

Lead-lag compensator

Accepted Answer

A control technique that adjusts the phase of a control signal to improve system response.

Question 19

Setpoint

Accepted Answer

The desired value of a controlled variable in a feedback control system.

Question 20

Error signal

Accepted Answer

The difference between the setpoint and the measured value of the controlled variable.

Question 21

Bode plot

Accepted Answer

A graphical representation of a system's frequency response, used to analyze and design control systems.

Question 22

Nyquist plot

Accepted Answer

A graphical representation of the gain and phase shift of a system as a function of frequency.

Question 23

Root locus

Accepted Answer

A graphical technique for determining the stability of a control system by plotting the poles and zeros of the transfer function.

Question 24

Transfer function

Accepted Answer

A mathematical representation of the relationship between a system's input and output.

Question 25

Time domain analysis

Accepted Answer

A method for analyzing control systems by examining their time response to various inputs.

Question 26

Frequency domain analysis

Accepted Answer

A method for analyzing control systems by examining their frequency response.

Question 27

Open-loop control system

Accepted Answer

A control system that does not use feedback to determine the control action.

Question 28

Closed-loop control system

Accepted Answer

A control system that uses feedback from the controlled variable to determine the control action.

Question 29

Steady-state error

Accepted Answer

The difference between the desired and actual value of a controlled variable after the system has reached a steady state.

Question 30

Overshoot

Accepted Answer

The maximum amount that a system's output exceeds its final steady-state value following a step input change.

Question 31

Settling time

Accepted Answer

The time it takes for a system's output to reach and remain within a specified range of its final steady-state value.

Question 32

Damping ratio

Accepted Answer

A measure of the degree of oscillation in a system's response

Question 33

Damping coefficient

Accepted Answer

A parameter that characterizes the amount of energy dissipation in a system, affecting the rate at which oscillations decay.

Question 34

Phase margin

Accepted Answer

A measure of the difference between the phase of a system's open-loop transfer function and -180 degrees at the gain crossover frequency.

Question 35

Gain margin

Accepted Answer

A measure of the difference between the gain of a system's open-loop transfer function and 0 dB at the phase crossover frequency.

Question 36

Ziegler-Nichols tuning

Accepted Answer

A method for determining the optimal PID controller parameters based on the system's ultimate gain and ultimate period.

Question 37

Process variable (PV)

Accepted Answer

The measured value of a controlled variable in a feedback control system.

Question 38

Manipulated variable (MV)

Accepted Answer

The variable that the controller adjusts in order to maintain the process variable at the desired setpoint.

Question 39

Disturbance variable (DV)

Accepted Answer

An external factor that influences the process variable, but is not controlled by the control system.

Question 40

Signal conditioning

Accepted Answer

The process of modifying a signal, such as amplification or filtering, to make it suitable for further processing or transmission.

Question 41

Two-wire transmitter

Accepted Answer

A transmitter that combines the power supply and signal transmission into a single two-wire connection.

Question 42

Fieldbus

Accepted Answer

A digital communication protocol used to connect field devices, such as sensors and actuators, to control systems.

Question 43

Human-machine interface (HMI)

Accepted Answer

A graphical interface that allows operators to monitor and interact with a control system.

Question 44

Supervisory control and data acquisition (SCADA)

Accepted Answer

A system for monitoring and controlling industrial processes remotely, typically using communication networks.

Question 45

Intrinsically safe (IS)

Accepted Answer

A design approach that ensures electrical equipment will not ignite an explosive atmosphere, even under fault conditions.

Question 46

Hazardous area classification

Accepted Answer

A system for defining the level of risk associated with the presence of explosive materials in a specific location.

Question 47

Signal-to-noise ratio (SNR)

Accepted Answer

A measure of the level of a desired signal relative to the level of background noise.

Question 48

Aliasing

Accepted Answer

The distortion of a sampled signal caused by insufficient sampling rate or poor filtering of high-frequency components.

Question 49

Total harmonic distortion (THD)

Accepted Answer

A measure of the amount of harmonic content in a signal, typically expressed as a percentage of the fundamental frequency.

Red Seal Exam: Instrumentation and Control Technician Flashcards