Et

Front 1

One of the oldest testing methods

Back 1

Electromagnetic testing

Front 2

--- discovered that a compass placed bear a wire transmitting an electric current tends to set itself perpendicular to the wire.

Back 2

Oersted

Front 3

The first scientist who discovered the effect of electromagnetic induction

Back 3

Faraday

Front 4

The first practical system for measurement of flux leakage fields was discovered by..

Back 4

Hasting

Front 5

Eddy current testing is based on the principles of

Back 5

Electromagnetic testing

Front 6

Means using electricity and sound waves

Back 6

Electromagnetic

Front 7

Magnetic flux leakage can be used by using what techniques

Back 7

Magnetic particle testing (wet or dry), hall effect probe, and induction coil

Front 8

The presence of ----- on or near the surface of a test object disturbs the magnetic flux lines and results in a local leakage field around the ----

Back 8

Discontinuity

Front 9

How many levels of nondestructive personnel certification are there

Back 9

3

Front 10

Qualification of nondestructive testing personnel should involve

Back 10

Training, experience, and pass written and practical test

Front 11

The electromagnetic field produced around the coil is directly proportional to

Back 11

Magnitude of applied current,rate of change in current, and coil parameters

Front 12

---- is defined as the movement of electrons through a conductor

Back 12

Electrical current

Front 13

The unit of electromagnetic force is called

Back 13

Volt

Front 14

The unit of resistance is

Back 14

Ohm

Front 15

Ohms law is stated in this equation

Back 15

E=ir

Front 16

The resistance of a coil is determined by

Back 16

The length of wire used to wind a coil

Front 17

The frequency of an alternating current is defined as the number of cycles of current that occur in one

Back 17

Second

Front 18

The opposition to changes in alternating current flow through a coil is

Back 18

Inductive reactance

Front 19

The unit of impedance is

Back 19

Ohm

Front 20

-- and the -- cause results that occur 90 degree out of phase with each other

Back 20

Resistance and the inductive reactance

Front 21

A basic Eddy current instrument circuit consists of

Back 21

Alternating current source, test coil(s), and display apparatus

Front 22

A display apparatus in an Eddy current instrument circuit can consist of

Back 22

Analog meter, cathode ray tube scope, lcd

Front 23

A Wheatstone bridge circuit consists of

Back 23

Alternate current source, balancing resistors, display apparatus, and testing coil

Front 24

When a test coil is placed on or near a test subject

Back 24

The impedance of the coil changes

Front 25

When the bridge in a Wheatstone bridge is in balance

Back 25

The display apparatus will read 0

Front 26

--- occurs in the electromagnetic field of the coils assembly

Back 26

Signal modulation

Front 27

Signal excitation, signal modulation, signal demodulation, and signal display are considered

Back 27

Internal functions of an Eddy current instrument

Front 28

The purpose of signal preparation is to

Back 28

Amplify the probe signal and reject extraneous noise

Front 29

The signal to noise ratio is defined as

Back 29

The ratio of signals of interest to unwanted signals

Front 30

It is standard nondestructive testing industry recommendation that signal o noise ratio should be at least

Back 30

3:1

Front 31

The purpose of saturation coil

Back 31

To improve signal to noise ration

Front 32

What would the best coil be to use on a 2 in tube

Back 32

The 213 coil would be the best

Front 33

In setting the sensitivity on the unit what must you make sure of

Back 33

Equal amplitude of alarm around the standard at 3 6 8 12 locations

Front 34

Why is it important to demag the tube after testing

Back 34

To remove as much residual magnetism as possible

Front 35

What is the easiest discontinuity to pick up on our unit

Back 35

A short abrupt type

Front 36

If you increase the number know the sensitivity setting do we get an increase\decrease in sensitivity

Back 36

Increase sensitivity

Front 37

What causes a defect to be detected on the ec

Back 37

There is a change in the coils impedance

Front 38

What are the acceptance standards of the test

Back 38

Only acceptable material that has passed being compared to a standard is to be passed

Front 39

What are the different types of artificial defects in standards

Back 39

Drilled holes, 1\4 filed transverse notch, longitudinal notch, and an ID chip

Front 40

How do you mark a reject

Back 40

Put reject tape on both sides of the reject

Front 41

How do we set the end suppression

Back 41

Set it to shut off as the tube end approaches

Front 42

What must we do if you run your standard and it doesn't pick up

Back 42

Recalibrare and rerun all the material since the last acceptable standard check

Front 43

If the alarm sounds on the unit what does that mean

Back 43

That a spot on the tube is interrupting at least as many Eddy currents as the reference standard

Front 44

What Is the operating frequency of your unit

Back 44

5 khz

Front 45

If a defect seems to move on the piece being tested what could be the cause

Back 45

Could be something in the tube

Front 46

Is the conductivity affected by temperature

Back 46

Yes

Front 47

What must be done after a tube has been tested

Back 47

Demaged

Front 48

How do we electronic center the standard

Back 48

Use the centering unit adjust meter to the centering position

Front 49

How often should the standard be run

Back 49

Beginning of the end of every order and every shift. Every 2 hours of long order. Anytime you suspect some things wrong

Front 50

The readout mechanism is the part of the Eddy current instrument that

Back 50

Quantified the change in the test coil impendance

Front 51

The read out mechanism can be

Back 51

Module that is plugged into the test set, integral part of the system, or separate device connected to the system

Front 52

The indicating device used in an Eddy current test system

Back 52

should meet the adequate speed,accuracy and range needed

Front 53

There a typically two typed if read out mechanisms used in Eddy current instruments

Back 53

Analog meters and digital displays

Front 54

Audio alarms indicate only

Back 54

Qualitative information that nay be caused by abnormal conditions

Front 55

The strip chard recorder is

Back 55

A read out device that produces permanent and fairly accurate record

Front 56

When evaluating a liquid crystal display the following factors should be considered

Back 56

Matrix type, resolution, and input viewing angle

Front 57

The combination of components from different test frequencies is known as

Back 57

Digital mixing

Front 58

Crts give contentious presentation of signals and are considered

Back 58

Accurate

Front 59

Digital storage and digital mixing are types of

Back 59

Digital displays used in Eddy current testing

Front 60

A surface probe can also be called

Back 60

Flat coil and absolute coil

Front 61

The magnetic field produced by a surface coil is approximately the size of the

Back 61

Coil

Front 62

Encircling coils are used to test ____ diameter surfaces of objects

Back 62

Outside

Front 63

Encircling coils are used to located discontinuities that are___ or ___ to the length of the rod

Back 63

Parallel or longitudinal

Front 64

The following are could that are used to inspect test objects from the inside diameter

Back 64

Bobbin coils, inside coils, inner diameter coils

Front 65

Test coil arrangements can be

Back 65

Absolute differential and hybrid

Front 66

Absolute coil arrangements can can be

Back 66

Single and double

Front 67

Differential coil arrangements can be either

Back 67

Self comparison or external comparison

Front 68

The through transmission technique involves inducing eddy currents into the subject by

Back 68

A transmitting coil places on one side of the material and the presence of eddy current is sensed by a receiving coil placed on the opposite side of the material

Front 69

The following are factors that affect the choice of test coils

Back 69

Frequency, sample rate, digitization , excitation, horizontal and vertical deviation, gain linearity, quadrature rate, sample rate, bandwidth

Front 70

Magnetic flux leakage is an electromagnetic technique that can provide quick assessment of the integrity of

Back 70

Ferromagnetic materials

Front 71

Magnetic flux leakage can be detected using the following sensord

Back 71

Induction coil and hall effect

Front 72

A ligament magnet can be considered an

Back 72

Agglomeration of domains

Front 73

The law of magnetism states that

Back 73

Like poked repel and unlike poles attract

Front 74

The unit of flux density is

Back 74

Gauss

Front 75

Flux density is defined as the number of lines of force

Back 75

That pass through a given area at a right angle to the lines of force

Front 76

According to the right hand rule, the direction of the magnetic field around the wire depends

Back 76

On the direction of the current flow through the wire

Front 77

If straight wire is wound into a coil

Back 77

The lined of force encircling the wire form the magnetic field inside and outside the coil

Front 78

All ferromagnetic materials have certain magnetic properties that are specific to that material

Back 78

Magnetic hysteria

Front 79

Magnetic permeability is calculated by the formula

Back 79

U=b\h

Front 80

Flux leakage sending elements can be the following

Back 80

Hall effect sensors, inductive coil sensors, and flux gate magnetomer

Front 81

Ferried are usually used in

Back 81

Pick up inductive sensors

Front 82

Ferrite materials have high or low electrical conductives

Back 82

Low

Front 83

In inductive coil applications, pick up could should be used to generate

Back 83

Voltages not currents

Front 84

When a voltage develops across the two faces of the crystal in a hall effect sensors, the voltage is

Back 84

Proportional to the strength of the magnetic field

Front 85

The flux gate magnetometer is also referred as

Back 85

Forster probe and ferry probe

Front 86

The flux density in an inductive coil must change through the coil in order to

Back 86

Produce a signal

Front 87

Hall elements are made of

Back 87

Semiconductive materials

Front 88

The following are considered methods of magnetic leakage field detection

Back 88

Magnetic tape system, magnetic particles, and magnetic resonance sensors

Front 89

Magnetic resonance sensor application is based on

Back 89

The fact that characteristic atomic frequencies also depend on the strength of the magnetic fields

Front 90

The approximate maximum of depth LG eddy current in our tubes is

Back 90

1\4 in

Front 91

Loop on graph

Back 91

Hysteresis loop

Front 92

Weird backwards u symbol

Back 92

Permability

Front 93

O symbol with tail

Back 93

Conductivity variable

Front 94

The depth of penetration decreases

Back 94

If you increase the frequency

Front 95

The time it requires to complete one cycle

Back 95

Period

Front 96

Unit of frequency

Back 96

Hertz