Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

instrumentation > Final > Flashcards

Final Flashcards

(55 cards)

Start Studying
1
Q

Two chemical reaction types.

A

Exothermic - gives off heat

Endothermic - absorbs heat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Self-Regulating process

A

Tank filling up while depleting

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

3 Process dynamic attributes

A

Gain - ratio of output to input
Lag - first change to completion
Deadtime - first change to first sensed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

2 things that contribute to lag in a process

A

Resistance

Capacitance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Difference between error and offset?

A

error - Difference in PV & setpoint

Offset - Permanent difference in measurement between PV and SP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

2 types of control loops

A

Open loop - feedforward

Closed loop - feedback

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Bump-less transfer?

A

Seamless transition from manual control to automatic control.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Two different control actions

A

Direct Control - as input increases output increases

Reverse Control - input increase output decreases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Deadband

A

Range of value where a change in measurement does not result in out change.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Four common control strategies

A

On/off - Two switch control, on & off
Proportional - changes output proportional to error.
Integral - changes output proportional to error and also factors in time.
Derivative - Changes output proportional to rate of change in a process.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

3 types of AI

A

Diagnostic - finds faults in a process
Knowledge - finds faults and probable cause
Expert - finds faults, probably cause, and a solution.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Proportional Gain

A

Input is proportional to the output

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Cascade Control

A

Multiple loop control strategy that alters the PV by changing the setpoint of the second loop.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

3 components of automatic control

A

Process variable - Dependent variable to be controlled.
Control variable - Independent variable used to adjust depend variable.
Controller - Device that compares a process measurement to a setpoint and changes the CV to bring the PV back to setpoint.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Controller tuning

A

Altering various inputs of a controller to achieve a desired output.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

The performance standards can often be defined by the ___ loop response of a ___ order system.

A

Closed, Second.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

3 common controller performance standards.

A

Deadtime - time between change is first made to first sensed.
Overshoot - Change of a PV that exceeds the uppder deadband.
Decay Ratio - How quickly an overshoot decays from one oscillation to the next.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Two reasons for using the most common performance standard.

A

It is easy to judge

Response is close to optimal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

3 Controller performance standards used in industry.

A

Rise time - the length of time required for PV to cross ultimate value.
Dynamic response time - Time it takes for pv to remain within 5% of its ultimate value
Gain margin - Gain is increased tot he point of instability.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

3 steps taken as a pretuning check.

A

Determine whether direct or indirect
Know if its proportional, integral, or derivative.
Know initial tuning values

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

4 manual tuning methods used for controller tuning.

A

Setpoint step change method - making small changes and observing.
Tuning Map Method - compares process curves to numerous others.
Ziegler-Nichols closed loop tuning - increasing gain to the point of instability
Ziegler Nichols open loop tuning - tuning based on open loop response to a step input.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Most common tuning method

A

Setpoint step change method - very easy to judge.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Another tuning method that is intended to achieve one-quarter decay ratio?

Study These Flashcards
A

Ziegler Nichols tuning method

24
Q

Digital controller

Study These Flashcards
A

Controller that uses microprocessor technology, digital version of electric controller.

25
Two differences between a DCS and PLC.
PLC's are more rugged | PLC's are faster
26
What are the two types of electric controllers
Null Balance | Analogue
27
3 operator interfaces
Stand alone display PC based display system Digital Recorder
28
5 commonly used configuration formats utilized in digital control systems.
Pick and choose - Picking and choosing between a config from a list of available functions. Ladder logic - 2 rails with sequential logic between them. Function Block - Library of functions provided by the manufacturer. Structured Text - Format similar to the C++ & microsoft visual basic Sequential Function Chart - series of conditional statements, parallel paths, and action block. Begins with start & ends with existing scan.
29
What is final element.
Receives a control input and adjusts material and energy accordingly.
30
How are the valve flow characteristics represented graphically?
Percent flow vs percent open
31
3 Valve flow characteristics
1. Quick-opening valve 2. Linear Valve 3. Equal-percentage valve
32
List and explain two phenomena that affect the control valves in liquid services.
1. Flashing - Liquid to vapor during pressure drops | 2. Cavitation - Vapor bubbles in liquid collapse inside a valve as pressure increases.
33
What is critical pressure ratio?
The ratio of downstream pressure to upstream pressure where gas out of a valve is at sonic velocity.
34
Cv
Valve coefficient, Q x √p/ΔP, number of gallons of water per minute at 60F.
35
What is the advantage of using a double ported valve over a single port valve?
Double ported valve reduces the force on the valve plug, and smaller actuator.
36
Name four types of rotary shaft valves
1. Butterfly 2. Ball 3. Plug 4. Eccentric Cam Control Valve
37
What is the difference between a pressure regulator and a back pressure regulator?
Pressure regulator monitors downstream pressure, while a back pressure regulator monitors upstream pressure.
38
List and Explain three types of dampers.
1. Parallel-blade Damper - A damper with adjacent blades that are in parallel. 2. Opposed-blade Damper - Damper, parallel blades, move in opposite direction. 3. Round-blade Damper - Damper that has a circular blade.
39
List four requirements of an actuator.
Speed Power Precision Resolution
40
List four types of actuators used on control valves.
1. Diaphragm and Spring Actuator 2. Pneumatic Sliding Stem Piston Actuator 3. Pneumatic Rotary Piston Actuator 4. Electric Actuator
41
What is the key feature of a typical valve positioner that allows for accurate positioning?
Feedback
42
Give two examples of processes that would use split range control.
1. pressure control | 2. Heating and cooling control valves
43
List and Explain the four types of pressure regulators.
1. Spring-Loaded Pressure Regulator - Valve plug that is controlled by spring opposition. 2. Air-Loaded Pressure Regulator - Uses air pressure to oppose and control downstream pressure. 3. Pilot-Operated Pressure Regulator - Uses upstream fluid pressure to power the diaphragm of a larger valve. 4. Differential Pressure Regulator - Controls pressure difference between the outlet pressure and inlet pressure.
44
Define PPE
Persona protective equipment, any clothing or device worn to protect injury.
45
What applications are safety vales, relief valves, and safety relief valves used?
Safety valves - conditions where valves must open quickly to reduce dangers. Relief valves - Used for unfired vessel applications, protection against overpressure down stream of pressure regulators. Safety relief valves - unfired vessels i.e. compressed air receiver vessels.
46
Difference between a safety valve and a safety relief valve?
Safety relief valves can act as both saefty valves and relief valves.
47
Pressure relief with the above valves must conform to codes established by whom?
ASME International (american society of Mechanical Engineers)
48
4 worst-case pressure-relieving conditions
Fire runaway chemical reaction blocked discharge thermal expansion
49
List and explain the four types of rupture disc.
Conventional metal - metal sheet placed between holders, with pressure applied to the concave side Reverse Buckling - metal sheet between holders, pressure on convex side. Composite - metal sheet with holes combined with thin polymer sheet. Graphite Composite - disc made of graphite powder in a polymer cement, used in corrosive conditions.
50
Name 2 types of hazardous atmosphere detectors.
Combustible gas detector | Toxic gas detector
51
3 electrical classifications for hazardous locations
Divisions Groups Classes
52
4 Electrical protections commonly used for instruments
Nonincendive protection Dust ignition proof protection Explosion proof protection Intrinsically safe protection
53
What is SIS
Safety Instrumented System, brings a process to a safe state when normal conditions are violated.
54
The use of an SIS to determine the required degree of safety is very complex, but the evaluation needs to consider ___, which is comprised of event ___ and event ___ and the ___ level needed to protect against it.
Risk Severity LIkelyhood Integrity
55
Difference between step change & load change
A load changed must be compensated for by the CV, whereas step change is compensated by the controller.

instrumentation (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions