basic asnt review 2nd Flashcards
(200 cards)
the most common frequency range of acoustic emission testing is
100-300 KHZ
Types of Discontinuity that are readily detectable by acoustic emission testing are
leak, plastic deformation, growing cracks
In acoustic emission testing, the total energy loss of a propagating wave is called
attenuation
the Kaiser effect refers to
the behavior where emission will not occur until the previous load is exceeded
The felicity effect is useful in evaluating
fiber reinforced plastic components
The Kaiser effect is useful in distinguishing
mechanical noise from growing discontinues
The terms counts refers to
the number of time a signal crosses a preset threshold
The acoustic emission signal amplitude is related to
the intensity of the source
In acoustic emission testing, threshold settings are determined by
the background noise level
In acoustic emission testing , background noise can be reduced by
electronic filtering
Eddy currents are circulating electrical currents induced in conductive materials by
Alternating magnetic field
The method used to generate eddy currents in the test specimen by means of a coil most closely compared with the action of a
Transformer
Eddy current testing relies on the principle of
Electromagnetic induction
When the electrical current in an eddy current coil reverses direction the
Direction of the eddy currents in the part also reverses
In order to generate measurable eddy currents in the test specimen, The specimen must be
An electrical conductor
The magnetic field generated by the eddy currents induced in the test specimen
Opposes the magnetic field that induced the eddy currents
In eddy current testing, IACS recognized abbreviation for
International annealed copper standard
In Eddy current testing, the specimen is coupled to the test coil by
The coils electromagnetic fields
The penetration of eddy currents in the conductive material is decreased when the
Test frequency, Conductivity of the specimen, or the permeability of the specimen is increased
At a fixed test frequency, in which of the following materials will the eddy current penetration be greatest
Lead (7% IACS conductivity)
A term used to describe the effect of observed due to a change in the coupling between a test specimen and a flat probe coil when the distance of separation between them is varied is
Lift off
When testing with eddy currents, discontinuity will be most easily detected when the eddy currents are
Perpendicular to the major plane of the discontinuity
Which of the following discontinuities is easiest to detect with eddy current test (subsurface crack lying parallel, discontinuity in the center of a bar stock, radial crack extended to the surface of a 2” bar, subsurface radial crack, a surface crack parallel to eddy currents)
A Radial crack that extends to the outer surface of a 51 mm or 2 inch diameter bar
The term used to define the timing relationship involved in alternating current signals is
Phase