Eddy Current- UR Flashcards
Which component of an eddy current inspection system induces eddy current into the part being tested?
coil assembly
What effect does a strong secondary magnetic field opposing the primary magnetic field have on depth of penetration in a material with high permeability?
reduced depth of penetration
when all other factors remain constant, what will a higher eddy current inspection frequency result in?
increased surface sensitivity and decreased depth of penetration
Usually, eddy currents are not useful as an inspection tool below….
3 standard depth of penetration
What is the minimum desired eddy current signal-to-noise ratio?
three to one
What do you call the adjustments you make to minimize the effect of eddy current probe proximity to the surface?
liftoff
When two elements of alternating current (AC) reach maximum, minimum, and zero points at different times, they are said to be?
out-of- phase
A plot of resistance and inductive reactance on a X-Y graph is called?
an impedance plane diagram
What control would you sue to change the display appearance or numerical parameters for a selected function on the Nortec 2000?
smartknob
how many test setups can be storeed in the Nortec 2000?
100
In simplest basic eddy current instrument, analysis of the signal consist of measuring the change in relative magnitude of the current flowing through the?
bridge circuit
What affects sensitivity and requires lift-off compensation during eddy current instrument standardization?
Paint thickness
you are using an eddy current probe to scan a part, the best way to reduce your chance of missing small cracks is to move the probe?
perpendicular to the direction of expected defects
Which material should not be used to make an eddy current probe fixture?
Steel
What must be done to the part before calibrating the eddy current instrument on the standard?
visually inspect for painted surface
What must you determine from the inspection procedure before selecting the correct standard to use?
whether the part is made of aluminum or steel
conductivity measurement is based on the?
International Annealled Copper Standard (IACS) system
Which is a typical application using conductivity measurement?
inspecting for changes in metal property
In degrees Fahrenheit, what is the worldwide standard temperature used to measure the conductivity of a standard?
68
When performing absolute conductivity with the Nortec 2000, what should you do after connecting the probe and turning the instrument on?
begin calibration by pressing the main function key
What must be done prior to calibrating an eddy current instrument for conductivity measurements?
allow the standards to reach the same temperature as the item under test
