Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
28 Cards in this Set
- Front
- Back
|
A device used to position dampers and control valves istermed a) a controller b) a relay c) a transformer d) an actuator e) a temperature controller |
d) an actuator |
|
|
Thermostats may be classified according to their a) application b) type of temperature sensing element c) type of control action provided d) temperature range e) all of the above |
e) all of the above |
|
|
On-off thermostats are equipped with: a) an open contact switch b) a high temperature switch c) a low temperature switch d) a high voltage switch e) a low voltage switch |
a) an open contact switch |
|
|
A bimetal thermostat's operating range is between: a) 5 and 40 degrees C b) 0 and 50 degrees C c) 0 and 40 degrees C d) 10 and 32 degrees C e) 50 and 90 degrees C |
d) 10 and 32 degrees C |
|
|
A room thermostat should be mounted on an inside wall about: a) 0.5 m above the floor b) 0.75 m above the floor c) 1.0 m above the floor d) 1.25 m above the floor e) 1.5 m above the floor |
e) 1.5 m above the floor |
|
|
Pressure controllers can be divided into two classes: a) high and low temperature b) high and low pressure c) high and low flow d) inside and outside mounting e) all of the above |
b) high and low pressure |
|
|
An example of a controlled device would be: a) a damper motor operating air louvers b) a hot water boiler c) a radiator d) a steam boiler e) a thermostat |
a) a damper motor operating air louvres |
|
|
Control motors are divided into two classifications: a) large and small b) AC and DC c) valve operators and damper operators d) high voltage and low voltage e) pump and fan controllers |
c) valve operators and damper operators |
|
|
In a basic electrical control system the device that senses adrop in air temperature is called the: a) final controlled device b) pneumatic temperature sensor c) humidistat d) thermostat e) regulator |
d) thermostat |
|
|
In a basic electric control system an example of a controlled device is: a) a fuel valve b) a louver c) a diverter valve d) an electric switch e) all of the above |
e) all of the above |
|
|
An electronic control system is comprised of a a) meter, sensor, and valve: b) sensor, controller, and final control element c) sensor, transmitter, and thermostat d) controller, thermostat, and sensor e) thermostat, electronic controls, and furnace |
b) sensor, controller, and final element |
|
|
An advantage of an electronic control system is that a) the controllers can accept a wide variety of inputs b) they are inexpensive to operate c) they are inexpensive to install d) the controllers can be used outdoors e) it is very compact |
a) the controllers can accept a wide variety of inputs |
|
|
An example of a final control element is a a) thermostat b) fire eye c) relay d) damper e) thermocouple |
d) damper |
|
|
An electronic controller is a) not part of the electronic control system b) used to position an actuator c) used to generate a set point d) a type of sensor e) used only in pneumatic systems |
b) used to position an actuator |
|
|
The electrical resistance of a thermistor will a) decrease when cooled b) decrease when heated c) increase when heated d) remain constant with temperature changes e) none of the above |
b) decrease when heated |
|
|
Resistance temperature devices can provide a relatively linear resistance variation from: a) -60 to 80 degrees C b) -40 to 120 degrees C c) -40 to 250 degrees C d) 0 to 100 degrees C e) 40 to 100 degrees C |
b) -40 to 120 degrees C |
|
|
Transmitters or transducers can measure a) temperature b) air flow c) air flow velocity d) water flow e) all of the above |
e) all of the above |
|
|
A pressure sensor converts pressure changes into a) an electrical signal b) a change in electrical resistance c) variables such as voltage, current, or resistance d) air pressure e) a temperature change |
c) variables such as voltage, current, or resistance |
|
|
Electronic controllers can be divided into two types a) on or off b) modulating and direct acting c) indirect and direct acting d) on or off and modulating e) actuators and relays |
d) on or off and modulating |
|
|
A transducer is a device that is used to: a) generate a set point b) produce an off or on signal c) convert an electronic signal to a pneumatic output d) amplify an electronic signal e) filter an electronic signal |
c) convert an electronic signal to a pneumatic output |
|
|
An advantage of an electronic control system over pneumatic systems is that: a) the controllers accept a wide variety of inputs b) they provide better control c) they are simple and easy to install d) the controller can be used outdoors |
c) they are simple and easy to install |
|
|
In a capacitor type control motor, the rotor and gear train are sealed inside a housing that is partially filled with: a) air b) oil c) antifreeze d) refrigerant |
b) oil |
|
|
Which of the following types of switching devices are used in conjunction with bimetal strips to control electric circuits? a) open-contact switch b) mercury bulb switch c) snap switch d) all of the above |
d) all of the above |
|
|
A heat anticipator gives a thermostat timed _____ position action to prevent the room temperature from overshooting. a) single b) two c) three d) multiple |
b) two |
|
|
An electronic controller is used to position: a) final control element b) an actuator c) an electronic instrument d) a transmitter |
b) an actuator |
|
|
Types of metals used to manufacture the wires used in RTD's are: a) nickel b) iron c) platinum d) all of the above |
d) all of the above |
|
|
Electric pneumatic transducers convert a modulating 2 to 10 V DC signal to a pneumatic signal of ____ to ____ kPa. a) 0, 90 b) 3, 15 c) 12, 120 d) 0, 125 |
a) 0, 90 |
|
|
An electronic pressure sensor consists of a ______ that converts pressure changes into different variables. a) thermistor b) transmitter c) thermocouple d) RTD |
b) transmitter |
