Which one is NOT an disadvantage of Pneumatic Signals?

Which one is NOT an disadvantage of Pneumatic Signals?

a. Always lag or delay in the signal
b. Friction causes a decrease in the value of the signal
c. More expensive than electronic instruments
d. Cost of tubing is greater than electrical wiring
e. Ensuring a clean, dry air supply may be costly.




Answer: C

Which one is NOT an advantage of Pneumatic Signals?

Which one is NOT an advantage of Pneumatic Signals?

a. They are simple and provide trouble free operation
b. They can transmit over long distances
c. Less expensive than electronic instruments
d. Safe in operation




Answer: B

The component of a control system that adjusts the value of the manipulated variable

The component of a control system that adjusts the value of the manipulated variable

a. Process variable
b. Final control element
c. Manipulated variable
d. Controlled variable
e. Transmitting variable





Answer: B

Indicates the value of the variable (pressure, level, or flow) being monitored or recorded on a chart for future reference.

Indicates the value of the variable (pressure, level, or flow) being monitored or recorded on a chart for future reference.

a. Transmitter
b. Controller
c. Indicator
d. Recorder
e. Process variable



Answer: D

Instantly show the values of different variables to the operators and maintenance personnel.

Instantly show the values of different variables to the operators and maintenance personnel.

a. Transmitter
b. Controller
c. Indicator
d. Recorder
e. Process variable




Answer: C

The margin by which an automatic controller misses the desired value

The margin by which an automatic controller misses the desired value

a. Agitation
b. Disruption
c. Disturbance
d. Error
e. Malfunction





Answer: D

When a process variable has no method of sending information to the final control element the system is known as

When a process variable has no method of sending information to the final control element the system is known as

a) an automatic system
b) an open loop system
c) a cascading system
d) feedback system
e) feedforward system



Answer: B

An upset in a plant process is called a/an:

An upset in a plant process is called a/an:

a. Agitation
b. Disruption
c. Disturbance
d. Error
e. Malfunction

Answer: C

Pneumatic signals operate between:

Pneumatic signals operate between:

a. 20 and 200 kPa
b. 0 and 100 kPa
c. 50 and 500 kPa
d. 20 and 100 kPa
e. 20 and 200 kPa






Answer: D

A controller is a device that primarily:

A controller is a device that primarily:

a. Sends or transmits a positive rather than negative signal
b. Tries to maintain a set point
c. Records a system's performance
d. Notifies operators of errors or faults in a system
e. Is a logic device capable of making decisions



Answer: B

Automatic systems that can make decisions are termed:

Automatic systems that can make decisions are termed:

a. Annunciation systems
b. Indicating systems
c. Logic systems
d. Open loop systems
e. Go-NoGo systems




Answer: C

In an automatic control system, the controller output signal changes the position of the:

In an automatic control system, the controller output signal changes the position of the:

a. Recorder
b. Transmitter
c. Sensing element
d. Control valve
e. Indicator dial




Answer: D

For a pneumatic control system, it is imperative that

For a pneumatic control system, it is imperative that

a. The maximum transmitter output signal pressure be maintained
b. The air supply is kept clean and dry
c. The control systems have built-in redundancy
d. The compressed air supply remains above 1725 kPa
e. The control devices are fitted with noise attenuators



Answer: B

A device which will cause a visible light signal to become an instrument analog signal is the:

A device which will cause a visible light signal to become an instrument analog signal is the:

a. Photoelectric transducer
b. Transferor
c. Controller
d. PE switch
e. Current-to-pneumatic transducer





Answer: A

An open loop control system requires:

An open loop control system requires:

a. A transducer and a recorder
b. More accurate sensing devices
c. A very small amount of dead time or lag
d. Constant operator attention
e. Two final control elements




Answer: D

Level, pressure, flow, temperature, composition, vibration, speed and clearance are all examples of:

Level, pressure, flow, temperature, composition, vibration, speed and clearance are all examples of:

a. Transmitters
b. Process variables
c. Sensing elements
d. Disturbances
e. Manipulated variables




Answer: B

A control loop controller:

A control loop controller:

a. Operates without a set point
b. Sends a signal to a primary element
c. Measures the manipulated variable value, eliminating the need of a primary element
d. Eliminates all setpoint deviation
e. Constantly compares input signals to the set point

Answer: B

The forms commonly used for power-plant equipment control include analog, digital, mechanical, pneumatic and:

The forms commonly used for power-plant equipment control include analog, digital, mechanical, pneumatic and:

a. Physical
b. Electrical
c. Manual
d. Thermal
e. Magnetic





Answer: B

Some of the components of an automatic control loop are a sensing element, a transmitter, a _____ and a control valve.

Some of the components of an automatic control loop are a sensing element, a transmitter, a _____ and a control valve.

a. Controller
b. Transformer
c. Transducer
d. Piping system
e. Converter




Answer: A

A sensing element sends its signal to a:

A sensing element sends its signal to a:

a. Transmitter
b. Controller
c. Control valve
d. Recorder
e. Process variable

Answer: A