11/05/2024 12:06 PM
Instrumentation & Controls BOMA Pre-
Quiz Exam Questions With Correct Answers
What important functions does an air receiver perform? - answer✔Dissipates heat,
Dampens compressor pulsations,
Act as water oil trap
On a compressed air system a safety valve would generally be installed on the? - answer✔Air receiver
Variable air volume system? - answer✔Typically use VFDs to save energy
In figure 1.3, a full call for cooling would be at what branch pressure to the damper motor? - answer✔3
psig
A ratio relay would be used to? - answer✔Control the sequence of actuators
When an actuated device is said to be normally open, that means the device is open with? - answer✔No
control pressure is applied
In figure 1.4, the hot water valve has an 8-12 psig spring range, the damper motor has a 3-5 psig spring
range. The calibration point of the thermostat is? - answer✔8 psig
When you are setting up an instrument, you should know all of the following except? - answer✔The rate
of flow of the control agent
Which of the following is an example of a control with a readjusted set point? - answer✔Submaster
controller
In figure 1.5, the branch pressure from the temperature controller increases the pressure as the? -
answer✔Controlled variable decreases in Temperature
The departure of the control point from the set point, or the amount of that departure is describe as ? -
answer✔Deviation
The action of a control that increases its branch pressure as the controlled variable increases? -
answer✔Direct acting
, ©THEBRIGHT EXAM SOLUTIONS
11/05/2024 12:06 PM
In figure 1.3 maximum heating would be at what branch pressure to the damper motor? - answer✔13
psig
In figure 1.0, if the hot water control valve was N/O instead of N/C, what would the action be? -
answer✔Direct acting
A three way mixing valve? - answer✔Has two inlets and one common outlet
What will the typical range of a current sensor be? - answer✔4-20 mA
In figure 1.4, with a loss of control branch pressure this system will fail on? - answer✔Full cooling
If you decrease the percentage of proportional band on a receiver controller you would in affect? -
answer✔Increase the psi/ degree Fahrenheit output of the control
The temperature- resistance characteristics of a thermistor is? - answer✔Non-linear
A reasonable consumption of control air for a thermostat would be? - answer✔30-40 scim
A static pressure regulator senses the pressure in the plenum, the sensor that indicates this pressure to
the regulator is called? - answer✔Static tip
An instrumentation system is designed to? - answer✔Perform a specific function in the specific process
If we lost control power in figure 1.2 the room temperature would ? - answer✔Fall/ decrease in
temperature
Which of the following sensors have only two points? - answer✔Digital
On or off
The sensing element on a humidstat is said to be made on hygroscopic membrane. All of the following
materials are considered hygroscopic except? - answer✔Carbon steel
A pneumatic controller takes air from the main at a ________ pressure and delivers it to the actuator at
a ____ pressure: - answer✔Constant, variable
Current outputs produce ______ signal distortion over long wire distances. - answer✔Low
A three-way diverting valve? - answer✔Has to outlets and one common inlet
A normally closed pressure electric switch is made when? - answer✔No air is applied to its bellows
In figure 1.4 the heating valve is piped ? - answer✔Normally closed
The intensity of heat is expressed in the terms of? - answer✔BTU's
Or