Chapters 35&36 Flashcards
Impedance is the opposition to the potential that moves material or energy in or out of a process.
True
A step change is a sudden change in an input variable in a process that is managed by a controller.
True
A time constant (t) is the measured time when an output response is 1.00 or 100% of an input step change.
False
Dead time is a delay in the response of a process that represents the time it takes for a process to respond completely when there is a change in the inputs to the process.
False
Capacitance is the ability of a process to store material or energy.
True
Lag time is the period of time that occurs between the time a change is made to a process and the time the first response to that change is detected.
True
An _ reaction is a chemical reaction that generates heat during the reaction and increases temperature. A. Endothermic B.Exothermic C. Enthalpic D. Entropic
B
An _ reaction is a chemical reaction that consumes heat, and more heat energy must be added to sustain the reaction. A. Enthalpic B. Entropic C. Endothermic D.Exothermic
C
A(n) _ curve is a plot of the PV against the CV. A.Open loop B. Process C. Closed loop D. Gain
B
A _ variable is an independent variable in a process control system that is used to adjust a dependent variable. A. Control B. Setpoint C.Dynamic D. Controller
A
A primary element is the sensing device that detects the condition of a _ variable. A. Control B. Process C. Setpoint D. Secondary
B
A _ variable is a dependent variable that is controlled in a control system. A. Manipulated B. Control C. Process D. Static
C
_____ is the equipment and techniques used to automatically regulate a process to maintain a desired outcome.
Automatic Control
_____ is the ratio of the change in output to the change in input of a process.
Gain
A(n) _____ process is a process where the gain at any point of the input range is the same as the gain at any other output.
LInear
Proportional gain is the gain, or sensitivity, of a control variable.
True
A proportional (P) control strategy is a method of changing the output of a controller by an amount proportional to the error.
True
ON/OFF control is a method that produces an output that provides only an ON or OFF signal to the final element of the process.
True
The reset rate is the reciprocal or integral time
True
ON/OFF proportional control is proportional control combined with both integral control and derivative control.
False
A(n) \_\_ output is an output that has a continuous range of possible output values between minimum and maximum limits. A. Digital B. Discrete C. Analog D. Binary
B
\_\_\_ is the range of values of an input that corresponds to a full range of output from a controller, stated as a percentage. A. Proportional band B. Throttling range C. Proportional Gain D. Integral Gain
A
\_\_\_ is a controller function that positions a final element in a central position when the process variable is at setpoint. A. Overshoot B. Integral gain C. Proportional gain D. Output Bias
D
\_\_\_ is the change of the PV that exceeds the upper deadband value when there is a disturbance to the system. A. Undershoot B. Gain C. Overshoot D. Tuning
C
A(n) \_\_ is the range values where a change in measurement values results in no change in controller output. A. Proportional band B. Lag C. Open loop D. Deadband
D
\_\_ control is a control strategy that only controls the inputs to a process without feedback from the output of the process. A. Feedback B. Feedforward C. Proportional D. ON/OFF
B
A(n) ____ ON/OFF controller is an ON/OFF controller that has a predetermined output period during which the output contact is held closed for a variable portion of the output period.
Time Proportional
___ is the change of the PV that goes below the lower deadband value when there is a disturbance into the system.
Undershoot
___ is the number of units of a process variable that causes an actuator to move through its entire range.
Throttling range
List and describe three components of a control loop: 1. 2. 3. Descriptions
1.Controller
Device that compares a process measurement to a setpoint and changes the control variable to ring back the PV to the setpoint.
2. Proportional Variable (PV)
Dependent variable that is to be controlled in a system.
3. Control Variable (CV)
Independent variable in the process control system to adjust to dependant variable.
List two types of chemical reactions and tell the difference.
1.
2.
Descriptions
- Exothermic- releases heat and let’s things expand
2. Endothermic heat- conserves heat and make things condense.
What is the difference between an Open and Closed loop?
Open loop doesn’t get feedback.
Closed loop does get feedback. Open loops let’s electricity flow easily closed loop does not.
What is the abbreviation, formula, and description of gain.
Abbreviation:
Formula:
Description:
Abbreviation: K
Formula: K=Input
\_\_\_\_\_\_\_\_\_
Output
Description: Gain is how sensitive the product is to the variations of change in the process.What are the two controller actions and the difference between them?
Direct- PV increase and CV increases
Reverse- controller action where the controller output decreases and the Process variable measurement increases.
List and define the three process dynamics:
1.
2.
3.
- Lag-
A delay in response of a process that represents the time it takes for a process to respond completely when there is a change in the inputs to the process. - Deadtime-
The period of time that occurs between the time change is made to a process and the time the first response to that change is detected. - Gain-
A ratio of the change in output to the change in input of a process.
What is Deadband?
Deadband-
The range of values where a change in measurement value does not result in a change in controller output.
What is Proportional Band?
Proportional Band-
The range of input values that corresponds to a full range of output from a controller, stated as a percentage%.
What is the difference between a step change and a load change?
Step Change-
A sudden change in an input variable in a process that is managed by a controller.
Load Change-
A change in process operating conditions that changes the process variable (PV) and must be compensated for by a change in the control variable (CV)
What is Output Bias, and what is the most common output bias?
Output Bias-
A controller function that positions a final element in a central position when the process variable is at setpoint.
Explain Transmitter Dynamic Gain:
Transmitter Dynamic Gain-
The amount of output change from a transmitter for a specific input change.
What is the difference between Controller Gain and Proportional Gain?
Controller Gain-
The gain, or sensitivity of a controller itself.
Proportional Gain-
The gain or sensitivity of a proportional term only.
