Quizzes 3-5

Question 1

The boiling point of a liquid can be increased if the pressure of the container in which it is held is ____________.

Answer 1

increased

Question 2

In a P&ID designation, the ______________ identifies the function of an instrument and the
variable that is being measured

Answer 2

first letter

Question 3

Generally speaking, the basic difference between an open loop and a closed loop control system is that a (n):

Answer 3

closed loop systems incorporate feedback

Question 4

The type of light typically emitted by the light source of an optical encoder is ______

Answer 4

infrared

Question 5

The _____________ is the sensing device that detects the condition of the process variable

Answer 5

primary element

Question 6

Which of the following transmitter output ranges can not be described as having a “live zero”?

Answer 6

0 - 10 V

Question 7

A “Variable Gain Error” in a measuring device is also known as a _____________ Error.

Answer 7

Linearity

Question 8

The hydrostatic pressure created by a liquid in a closed container __________ when its temperature increases.

Answer 8

increases

Question 9

Of the following devices, which one is used for sensing the position of an object by measuring
the time it takes for a pulse to be echoed back?

Answer 9

The ultrasonic transducer

Question 10

A magnetic flowmeter won’t work on non conductive fluids T/F

Answer 10

True

Question 11

RTDs, thermistors and strain gauges are essentially resistors. T/F

Answer 11

True

Question 12

What testing an RTD or a thermistor, why is it necessary to disconnect it from the circuit?

Answer 12

The transducer must be isolated from the other circuit components that would affect the measurement

Question 13

The RTD’s resistance-temperature response is

Answer 13

more linear than that of the thermistor

Question 14

What type of energy can be converted into an electrical signal by an input transducer?
light
heat
force
all of the above

Answer 14

all of the above

Question 15

Which of the following transducer’s output would be a change of resistance?
Thermistor
RTD
Strain gauge
All of the above

Answer 15

All of the above

Question 16

A double-ported (double-seated) valve provides better closure that a single-ported (single-seated valve) T/F

Answer 16

True

Question 17

What is a controller?

Answer 17

A device that manages a process or product

Question 18

The error signal in a closed-loop control system is:

Answer 18

the difference between the set-point & feedback signal

Question 19

A “Bias error” is the same as a “Zero error.” T/F

Answer 19

True

Question 20

Which of the following Transducers are considered to be ? “active? ” Transducers?

Answer 20

Piezo Crystal

Question 21

What are the common Industrial electronic signal standards used in current and in voltage signal systems?

Answer 21

4 ~ 20 mA and 0 ~ 10 V

Question 22

Pressure varies the value of capacitance in a variable capacitor pressure sensor by changing __________.

Answer 22

the distance between the plates

Question 23

Pressure can be used to measure the height of liquid in a container. T/F

Answer 23

True

Question 24

Hydrostatic head pressure is at the __________ of a full tank.

Answer 24

sensor location

Question 25

In a differential pressure flow meter, the velocity of a fluid leaving the orifice plate is __________ the fluid that approaches it.

Answer 25

greater than

Question 26

In a transit time ultrasonic flow meter, the time difference between upstream and downstream ultrasonic signals becomes __________ as the velocity of the fluid increases.

Answer 26

greater

Question 27

An RTD increases its resistance when it is exposed to _________________.

Answer 27

heat

Question 28

A thermocouple produces a voltage that is proportional to the __________.

Answer 28

difference in temperature between the hot and cold junction

Question 29

The radiated energy of a blackbody is ______________

Answer 29

1

Question 30

When current is initially applied to a series circuit with a thermistor, its resistance is __________.

Answer 30

high

Question 31

An on/off control system ____. is relatively inexpensive is easy to design lacks precision all of the above

Answer 31

all of the above(this right)

Question 32

____ control valves are not used for high pressure application.

Answer 32

Single-seated

Question 33

All of the instruments in one loop are given the same loop number. T/F

Answer 33

True

Question 34

What is the basic difference between an open loop and a closed loop control system?

Answer 34

Closed loop has negative feedback.

Question 35

Control can be applied using several methods including, but not limited to, feedback. T/F

Answer 35

True

Question 36

The _____ letter of a functional identifier indicates the type of measured variable

Answer 36

First

Question 37

Sensors and transmitters are often combined into one unit. T/F

Answer 37

True

Question 38

A transducer is usually a (n): Output device Input device Sensor All of the above

Answer 38

All of the above

Question 39

A “Span error” in a measuring device is an indication of incorrect “Gain.” T/F

Answer 39

True

Question 40

Which of the following conditions cause the density of a fluid to increase?

Answer 40

a decrease in temperature an increase in pressure

Question 41

The point at which the liquid in a tank and the air above it are in contact is referred to as the __________.

Answer 41

interface

Question 42

The reference pressure of a gage pressure scale is __________.

Answer 42

the atmospheric pressure at sea level

Question 43

The greater the velocity the fluid flows through an orifice, the __________ the differential pressure that develops across it.

Answer 43

greater

Question 44

For the flow meter above, the signal output with a decreasing flow would be:

Answer 44

An AC value of decreasing magnitude

Question 45

The RTD is composed of

Answer 45

metal wire or film

Question 46

Strain gauge sensors produce large resistance changes in response to strain: T/F

Answer 46

True

Question 47

When a thermocouple is heated it generates a voltage due to the

Answer 47

Seebeck effect

Question 48

Which device is an output transducer?

Answer 48

Speaker

Question 49

Common types of ________________ elements are control valves, hydraulic pistons, variable speed drives, relays, pumps, and dampers

Answer 49

final