Liquid Penetrant Inspection (LPI)
This physical property allows penetrant to seep into cracks.
What is capillary action? (Ref: TO 33B-1-1, 2.5.2)
These are the two basic methods of magnetization used in MT.
What are longitudinal and circular magnetization? (Ref: TO 33B-1-1, 3.2.2)
This term describes the weakening of eddy currents with depth in the material.
What is the skin effect? (Ref: TO 33B-1-1, 4.3.3)
The most basic UT data display plotting amplitude vs. time.
What is an A-scan? (Ref: TO 33B-1-1, 5.4.4.1)
This law states that radiation intensity decreases with the square of the distance.
What is the Inverse Square Law? (Ref: TO 33B-1-1, 6.7.3)
These are the three primary developer types used in penetrant inspection.
What are dry powder, aqueous/wet, and nonaqueous developers? (Ref: TO 33B-1-1, 2.6.2)
This type of current produces the greatest skin effect.
What is alternating current (AC)? (Ref: TO 33B-1-1, 3.2.4)
The instrument response when a crack interrupts eddy currents is seen as this.
What is the skin effect? (Ref: TO 33B-1-1, 4.3.3)
This material property affects wave transmit speed and must be known to calculate thickness.
What is sound velocity? (Ref: TO 33B-1-1, 5.2.2)
These image quality tools verify the sensitivity of radiographs.
What are IQIs (Image Quality Indicators)? (Ref: TO 33B-1-1, 6.3.9)
The minimum light intensity required for visible penetrant inspection.
What is 100 foot-candles (1076 lux)? (Ref: TO 33B-1-1, 2.5.4)
This technique ensures subsurface indications are detected by MT.
What is using direct current (DC) magnetization? (Ref: TO 33B-1-1, 3.2.5)
The property of a material that most directly influences ET signal phase.
What is permeability? (Ref: TO 33B-1-1, 4.2.2)
The law governing the refraction of ultrasonic waves at an interface.
What is Snell’s Law? (Ref: TO 33B-1-1, 5.7.2)
The ability of a radiograph to distinguish between small differences in thickness or density.
What is radiographic contrast? (Ref: TO 33B-1-1, 6.2.2)
This step removes excess penetrant from the inspection surface.
What is the penetrant removal step? (Ref: TO 33B-1-1, 2.5.3)
After inspection, this process reduces residual fields that could affect future use of the part.
What is demagnetization? (Ref: TO 33B-1-1, 3.4.11)
A standard depth of penetration corresponds to this percentage of current remaining.
What is 37%? (Ref: TO 33B-1-1, 4.3.4)
This type of wave propagates by particle motion perpendicular to the direction of travel.
What is a shear wave? (Ref: TO 33B-1-1, 5.3.3)
This type of radiation is used for very thick or dense materials when X-rays are insufficient.
What are gamma rays? (Ref: TO 33B-1-1, 6.4.3)
This type of penetrant system is most sensitive but requires strict control of contamination.
What is fluorescent post-emulsifiable penetrant? (Ref: TO 33B-1-1, 2.3.4)
The two methods of applying magnetic particles during inspection.
What are the continuous and residual methods? (Ref: TO 33B-1-1, 3.4.4)
This type of coil arrangement is used to cancel lift-off and increase flaw sensitivity.
What is a differential coil? (Ref: TO 33B-1-1, 4.4.2)
In immersion testing, this distance must be controlled to prevent near-surface signal loss.
What is the water path distance? (Ref: TO 33B-1-1, 5.6.4)
This effect produces scattered radiation that reduces image quality.
What is Compton scatter? (Ref: TO 33B-1-1, 6.7.5)