CRI Radiographic Film Interpretation 2 — Questions and Answers
Question 1: On a weld radiograph, a linear indication running parallel to the weld axis and located at the weld toe is most likely which discontinuity?
- Undercut (Correct answer)
- Longitudinal crack
- Incomplete fusion
- Slag inclusion
Correct answer: Undercut
Undercut appears as a dark linear indication at the weld toe, parallel to the weld axis, caused by melting of the base metal during welding.
Question 2: Which radiographic technique factor most directly controls the density (overall blackening) of a film?
- Kilovoltage (kV)
- Milliampere-seconds (mAs) (Correct answer)
- Source-to-film distance (SFD)
- Film type
Correct answer: Milliampere-seconds (mAs)
Milliampere-seconds (mAs) controls the quantity of radiation and therefore the overall film density.
Question 3: A radiograph shows a cluster of small, rounded dark spots scattered throughout the weld. This is most characteristic of:
- Porosity (Correct answer)
- Tungsten inclusions
- Burn-through
- Lack of penetration
Correct answer: Porosity
Scattered rounded dark spots are the classic radiographic appearance of gas porosity trapped in the weld metal.
Question 4: When using the double-wall single-image (DWSI) technique on pipe, the source is positioned:
- Inside the pipe centered on the weld
- Outside the pipe, with film inside
- Outside the pipe, with film on the same side as the source
- Outside the pipe, with film on the opposite side (Correct answer)
Correct answer: Outside the pipe, with film on the opposite side
In DWSI, the source is outside the pipe and the film is placed on the diametrically opposite outside surface, imaging only the near wall of the weld.
Question 5: The term 'radiographic sensitivity' refers to:
- The ability of film to detect small changes in radiation intensity
- The speed at which film develops
- The minimum detectable discontinuity size as a percentage of material thickness (Correct answer)
- The ratio of scattered to primary radiation
Correct answer: The minimum detectable discontinuity size as a percentage of material thickness
Radiographic sensitivity is the ability to detect the smallest significant discontinuity, expressed as a percentage of the section thickness.
Question 6: A 'cold lap' or 'overlap' discontinuity in a weld radiograph typically appears as:
- A rounded bright spot
- A smooth, curved dark line at the weld edge (Correct answer)
- An irregular bright linear indication
- A centrally located dark line
Correct answer: A smooth, curved dark line at the weld edge
Overlap (cold lap) appears as a smooth, curved dark line at the weld edge where molten metal flowed over cold base metal without fusing.
Question 7: Which IQI (image quality indicator) is placed on the SOURCE side of the test object whenever possible?
- Wire-type IQI only
- Hole-type (plaque) IQI only
- Both wire-type and hole-type IQIs (Correct answer)
- IQIs are always placed on the film side
Correct answer: Both wire-type and hole-type IQIs
Both wire-type and plaque-type IQIs should be placed on the source side to provide a more demanding (conservative) sensitivity measurement.
CRI Radiographic Film Interpretation 2
On a weld radiograph, a linear indication running parallel to the weld axis and located at the weld toe is most likely which discontinuity?