Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

ndi > Eddy current > Flashcards

Eddy current Flashcards

1
Q

which component in an eddy current inspection system provides current to the test coil?

A

oscillator

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

which component converts changes in eddy current magnitude and distribution into signals to be processed?

A

bridge circuit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what effect does high conductivity have on eddy current depth of penetration?

A

reduced depth of penetration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what’s the term for signal changes caused by the eddy current field intercepting a corner of a part?

A

edge effect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

if all other factors remain unchanged what effect does higher frequency have on eddy current depth of penetrations?

A

shallower depth of penetration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what’s the definition of the standard depth of penetration of eddy currents?

A

point where eddy current strength drops to 36.8% of surface strength

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

how many times deeper than the standard depth of penetration is the effective depth of penetration?

A

3 times

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what’s the desirable signal-to-noise ratio for flaw detection?

A

3 to 1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

how can you eliminate line voltage fluctuations that may be affecting your signal-to-noise ratio?

A

switch to a battery powered unit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

based on application, what are the three general classifications of eddy current probes?

A
  1. surface 2. Inside diameter (ID) 3. Encircling
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what characteristics of a probe determine the surface area inspected?

A

diameter of the probe and any shielding in the probe

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what type of eddy current probes concentrate the field directly under the coil and overcome many of the problems associated with edge effect?

A

shielded probes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what’s the definition of impedance?

A

total opposition to the flow of AC in an eddy current coil

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Where do phase angles form?

A

where the sine waves, representing 2 elements of AC, cross

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What does the line (formed on a CRT) between the dot with the probe off the part (Po) and the dot when the probe is placed on the part (P1) represent?

A

lift off

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

how can you configure impedance plane instruments to measure amplitude changes only?

A

calibrate the unit in the sweep display mode

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

how much operating time remains when the low-battery indicator indications appears?

A

1/2 hour

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Which control on the Nortec 2000 is used to adjust numerical parameters or the display appearance, depending on the function selected?

A

smartknob

19
Q

What key is pressed on the Nortec 2000 to display information to adjust the basic operating conditions of the unit, such as frequency or gain?

A

MAIN/FILTER key

20
Q

Which function key will activate the bolt hole scanner controls?

A

SETUP/SPECIAL key

21
Q

Which of the two immediate executions keys is used to execute an instrument operation or respond to a prompt?

A

ENTER key

22
Q

Which menu soft key would you press after the MAIN key in order to change horizontal and vertical gain together?

A

press gain menu soft key after you’ve pressed the MAIN key

23
Q

What is the operating frequency range of the Nortec 2000?

A

100 Hz to 12Mhz

24
Q

what two ways can the phase angle or rotation be set?

A

using the smartknob or INC/DEC keys

25
Q

Which two keys must be pressed before you can adjust the sweep with the smartknob?

A

first the DISP key then the DISPLAY key

26
Q

From which menu would you start to reset the unit to factory default settings?

A

SETUP menu

27
Q

Where should the flying dot be located after nulling is complete?

A

50 percent full screen height and 50% full screen width

28
Q

What must you make sure of when placing the probe on the crack standard?

A

make sure probe is on a good area away from any cracks

29
Q

When is the sensitivity check required?

A

when using the Air Force General Purpose reference standard

30
Q

during surface flaw detection, how would you estimate a discontinuity’s size?

A

by comparing it’s indication with your crack standard’s indication

31
Q

how should you scan a part to avoid missing small cracks?

A

move the probe perpendicular to the probable direction of defects

32
Q

what materials should not be used to make eddy current fixtures?

A

conductive materials

33
Q

what happens to an eddy current signal from defects of the same size as one of the defects increases in depth below the surface?

A

it decreases

34
Q

What is the most important dimension of a crack?

A

depth

35
Q

What’s the most important fact about the AF general Purpose Eddy Current Standard?

A

it is the only authorized eddy current standard to be used without a specific waiver

36
Q

what are three examples of artificial defects in eddy current standards?

A
  1. EDM 2. Saw 3. Machine notches
37
Q

what is the primary purpose of any standard?

A

provide you with a uniform response directly related to the condition or material property you are detecting or measuring

38
Q

What two fators must be tightly controlled during manufacture of an eddy current standard?

A

material specification and fabrication requirements

39
Q

What system is conductivity measurement based on?

A

International Annealed Copper Standard (IACS)

40
Q

What shim thickness is used when calibrating the Nortec 2000 liftoff for conductivity testing?

A

0.004 inch

41
Q

What do you isolate when you look for specified amount of conductivity change?

A

heat damage

42
Q

What temperature difference between the standards and the part will prevent your from performing conductivity testing?

A

10 degrees F or more

43
Q

What must you do if during conductivity testing you discover the calibration of the instrument is no longer valid?

A

recheck all readings taken since last calibration once unit is recalibrated

ndi (13 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions