Eddy Current Testing NDT classroom
questions and answers
Variations in the chemical composition of a Non-Ferromagnetic alloy would have the most effect
on its: - ANS ✔✔Conductivity
A reference sample used to ensure that the amplitude and phase characteristics of a test system
do not drift during continuous testing is call a: - ANS ✔✔Calibration standard
A term used to define a standardized condition in a device or system which results in zero
output shown across a bridge circuit is: - ANS ✔✔Null or Balance
When inspecting products with a uniform cross section, an eddy current signal is produced
when the leading edge or trailing edge of the product approaches the test coil. The
phenomenon is referred to as: - ANS ✔✔Edge Effect
The use of ferromagnetic shielding materials around the AC Coil will generally: - ANS
✔✔Decrease the magnetic field extension and decrease eddy current penetration.
Which of the following is not true about eddy current testing? - ANS ✔✔It can penetrate up to 2
inch. in a test part.
Eddy current always travels: - ANS ✔✔In closed paths
Eddy currents can not be induced in: - ANS ✔✔Paint
, Which of the following conditions would be the most difficult to detect when using an eddy
current testing rod with an encircling coil? - ANS ✔✔A small inclusion in the center of the rod.
When conducting an eddy current test using a coil arrangement that compares an external
reference standard with the specimen, the system should be nulled or balanced: - ANS ✔✔With
the reference standard in one coil and an acceptable test specimen in the other coil.
During an eddy current test discontinuities will be most easily detected when the eddy currents
are: - ANS ✔✔Perpendicular to the major dimension of the discontinuity.
An eddy current system is least sensitive to discontinuities that: - ANS ✔✔Are in the same plane
as the eddy current flow.
A term used to describe a hole, groove, or notch that is machined into the reference standard to
provide accurately reproducible quality level is: - ANS ✔✔Artificial discontinuity
A term used to define one or more turns or loops of a conductor wound in such a manner as to
produce an axial magnetic field when current passes through the conductor is: - ANS ✔✔A coil.
A test coil's opposition to the flow of alternating current is called: - ANS ✔✔Impedance
Non-destructive tests aren't conducted to: - ANS ✔✔Assure large volumes of material are
available for sale.
Which of the following is not a primary purpose for using a reference standard? - ANS
✔✔Determine the instrument control settings needed to pass the highest percentage of the
test specimens run.
In order to decrease the effect on conductivity readings due to variations in test part thickness: -
ANS ✔✔The test frequency should be increased
questions and answers
Variations in the chemical composition of a Non-Ferromagnetic alloy would have the most effect
on its: - ANS ✔✔Conductivity
A reference sample used to ensure that the amplitude and phase characteristics of a test system
do not drift during continuous testing is call a: - ANS ✔✔Calibration standard
A term used to define a standardized condition in a device or system which results in zero
output shown across a bridge circuit is: - ANS ✔✔Null or Balance
When inspecting products with a uniform cross section, an eddy current signal is produced
when the leading edge or trailing edge of the product approaches the test coil. The
phenomenon is referred to as: - ANS ✔✔Edge Effect
The use of ferromagnetic shielding materials around the AC Coil will generally: - ANS
✔✔Decrease the magnetic field extension and decrease eddy current penetration.
Which of the following is not true about eddy current testing? - ANS ✔✔It can penetrate up to 2
inch. in a test part.
Eddy current always travels: - ANS ✔✔In closed paths
Eddy currents can not be induced in: - ANS ✔✔Paint
, Which of the following conditions would be the most difficult to detect when using an eddy
current testing rod with an encircling coil? - ANS ✔✔A small inclusion in the center of the rod.
When conducting an eddy current test using a coil arrangement that compares an external
reference standard with the specimen, the system should be nulled or balanced: - ANS ✔✔With
the reference standard in one coil and an acceptable test specimen in the other coil.
During an eddy current test discontinuities will be most easily detected when the eddy currents
are: - ANS ✔✔Perpendicular to the major dimension of the discontinuity.
An eddy current system is least sensitive to discontinuities that: - ANS ✔✔Are in the same plane
as the eddy current flow.
A term used to describe a hole, groove, or notch that is machined into the reference standard to
provide accurately reproducible quality level is: - ANS ✔✔Artificial discontinuity
A term used to define one or more turns or loops of a conductor wound in such a manner as to
produce an axial magnetic field when current passes through the conductor is: - ANS ✔✔A coil.
A test coil's opposition to the flow of alternating current is called: - ANS ✔✔Impedance
Non-destructive tests aren't conducted to: - ANS ✔✔Assure large volumes of material are
available for sale.
Which of the following is not a primary purpose for using a reference standard? - ANS
✔✔Determine the instrument control settings needed to pass the highest percentage of the
test specimens run.
In order to decrease the effect on conductivity readings due to variations in test part thickness: -
ANS ✔✔The test frequency should be increased
