balancing

Question 1

eccentricity occurs when a rotating centerline of a rotor is not the same as the shaft axis and appears at a frequency of 1 x RPM
(1 Point)

true

false

Answer 1

true

Question 2

the most common shaft bends result from stresses locked up in shafts from
(1 Point)

grinding

heat treating

manufacturing operations

all the above

Answer 2

all the above

Question 3

static imbalance has the following characteristics
(1 Point)

is single plane

shafts weight is unevenly distributed from side to side

vibrations are very complex

both the 1st and 2nd answers are correct

Answer 3

both the 1st and 2nd answers are correct

Question 4

asymmetrical weight distribution is when a rotating part is balanced
(1 Point)

true

false

Answer 4

true

Question 5

dynamic imbalance is caused by
(1 Point)

extra weight unevenly distributed along the shaft length

extra weight unevenly distributed across the width of shaft

extra weight unevenly distributed at different angles about the radius

all the above

Answer 5

all the above

combination of static and couple imbalance and is the most common can only be measured when the part is rotating

Question 6

when components of significant length require 2 weights at opposing ends to balance the rotor, this is called
(1 Point)

static balancing

dual plane balancing

couple balancing

single plane balancing

Question 7

the amount of force caused by the lack of balance is proportional to the _______________
(1 Point)

RPM tripled

force squared

RPM squared

force tripled

Answer 7

rpm squared
imbalance force is quadrupled

Question 8

during the balancing procedure calculate a trial weight sufficient to change the amplitude of the vibration by _____%
(1 Point)

10

20

30

50

Answer 8

30

Question 9

.attach vibration transducers in the direction of highest amplitude (vertical, horizontal or axial)
(1 Point)

true

false

Question 10

to determine the trial weight size, use a weight that will produce an imbalance force at the support bearing equal to _______% of the rotor weight supported by the bearing
(1 Point)

5

10

20

50

Answer 10

10

Question 11

to determine the trial weight size you need to know the rotor weight, rpm and radius at which the weight will be placed
(1 Point)

true

false

Answer 11

true

Question 12

.if the correction weight can not be added at the same radius as the trial weight, the weight amount must be adjusted so that
(1 Point)

the weight angle stays the same

the product of the correction weight and the radius must be equal to the product of the adjusted weight and new radius

both the first and 2nd answers are correct

none of the above

Answer 12

both the first and 2nd answers are correct

Question 13

80.when adding 2 correction weights that were calculated for a fan (so some of the weight can be added to 2 fan blades), you must add them at the same radius as the trial weight
(1 Point)

true

False

Answer 13

true

Question 14

1 hertz is equal to
(1 Point)

1 cycle / minute

60 cycles / hour

60 cycles / second

none of the above

Answer 14

1 cycle / minute

Question 15

displacement is
(1 Point)

the total distance a vibrating part moves either side of its neutral axis.

its speed and direction

acceleration

cycles of vibration

Answer 15

the total distance a vibrating part moves either side of its neutral axis.

Question 16

.velocity is
(1 Point)

a combination of speed and direction of the vibration

the distance of movement of an object from its original position

measured in mils

measured in hertz

Answer 16

a combination of speed and direction of the vibration

Question 17

.acceleration is
(1 Point)

measured in inches / second

measured in G’s

measured in mils

measured in hertz

Answer 17

measured in G’s

Question 18

amplitude will answer the the question how much is it vibrating it provides the size ,severity of the vibration true or false

Answer 18

true

Question 18

when describing vibration amplitude with displacement, velocity and acceleration, the deciding factor is
(1 Point)

phase

pulse

critical speed

frequency

Answer 18

phase

Question 19

what is resonant frequency

Answer 19

can destroy amchjines an can lead to catrostproc failure

Question 20

machines should not be operatorated Ator near the critical speed they should operate how much out side of the rotors critical speed

Answer 20

20-30 percent

Question 21

a transducer that is used to measure all of the parameters of vibration (displacement, velocity and acceleration) is a
(1 Point)

displacement

phase

acceleration

none of the above

Answer 21

acceleration

Question 22

if a shaft is running at the same CPM as the natural frequency of the machine, it will be in
(1 Point)

harmonic balance

phase

resonance

period

Answer 22

resonance

Question 23

particle counters use an ISO cleanliness standard using _________ microns
(1 Point)

4, 8, 16

4, 6, 14

5, 10, 15

5, 7, 15

Answer 23

4, 6, 14

Question 23

in analytical troubleshooting, you will need to identify the problematic symptoms and (1 Point) determine the most likely cause from the data implement a corrective action plan use reactive maintenance procedures both the 1st and 2nd answers are correct

Answer 23

both the 1st and 2nd answers are correct

Question 24

fault tree analysis uses __________________ to represent root causes of the fault (1 Point) logic symbols item boxes arrows all the above only the first and second is correct

Answer 24

all the above

Question 25

.the time it takes for the dye to be drawn back to the surface (by capillary action) and into the developer is the dwell time true false

Answer 25

false

Question 26

an advantage of eddy current testing is it can detect laminar flaws can detect flaws at a deep depth can detect coating thicknesses including deposits and sludge none of the above

Answer 26

can detect coating thicknesses including deposits and sludge

Question 27

symmetrical weight distribution is when a rotating part is balanced

Answer 27

false

Question 28

truewhen components of significant length require 2 weights at opposing ends to balance the rotor, this is called static balancing dual plane balancing couple balancing single plane balancing false

Answer 28

dual plane

Question 29

the most common cause of vibration in machinery at 1 x rpm is misalignment unbalance bearing damage mechanical looseness

Answer 29

unbalance. right answer if two of these cards here

Question 30

when measuring vibration amplitudes of 60,000 CPM or higher, you would use displacement velocity acceleration Mils

Answer 30

acceleration

Question 31

when describing vibration amplitude with displacement, velocity and acceleration, the deciding factor is phase pulse critical speed frequency

Answer 31

frequency. right answer if two cards

Question 32

phase is the relationship between 2 or more events is measured in degrees angle is determined with the use of a strobe light all the above

Answer 32

all the above right answer if two cards

Question 33

fatigue fractures have which of the following shear lip beach marks ratchet mark all the above the first and second only

Answer 33

all the above

Question 34

when using RT, the slag inclusions or holes in the welds will be less dense, causing the film to be lighter in these areas when the film is developed true or False

Answer 34

false inclusions are darker