Radiography Level II Practice Questions, Verified Against ASME Section V

Questions 1-3: IQI selection and what sensitivity means

Question 1. A hole-type IQI is stamped 20. What is its thickness and what are its three hole diameters? Answer: the plaque is 0.020 in thick, and the 1T, 2T and 4T holes are 0.020 in, 0.040 in and 0.080 in in diameter. The designation number is the plaque thickness in thousandths of an inch, and the hole diameters are one, two and four times that thickness. The essential hole named in the selection table is the hole that must be clearly visible on the radiograph for the technique to be acceptable — not merely present on the plaque.

Question 2. A 7 mm single-wall weld must be radiographed with the IQI on the film side because the source-side surface is inaccessible. What do you place, and what else must appear on the film? Answer: hole-type designation 12 with a 2T essential hole, plus a lead letter F adjacent to or immediately below the IQI. Film-side placement calls for an IQI one designation number thinner than the source-side value for the same thickness range, because the IQI sits closer to the film and images more easily. The reason source-side placement was impractical is recorded with the examination.

Question 3. How many IQIs does a 400 mm long single exposure need, and what about a full-circumference panoramic shot? Answer: two for the 400 mm exposure, one near each end, because a single exposure longer than 250 mm requires an IQI at each end. A panoramic exposure covering a full circumference in one shot requires at least three IQIs spaced approximately 120 degrees apart. Where several welds are radiographed simultaneously, each weld carries its own IQI. The count exists to prove sensitivity across the whole area of interest, not at one convenient point.

Questions 4-6: Density, latitude and the densitometer

Question 4. State the density limits for single-film and composite viewing. Answer: through the body of the designated hole IQI and through the area of interest, single-film viewing requires 1.8 minimum for radiographs made with an X-ray source and 2.0 minimum for radiographs made with a gamma-ray source. For composite viewing of multiple film exposures, each film of the composite set requires 1.3 minimum. Maximum density is 4.0 for either single or composite viewing. The gamma minimum is higher because gamma sources produce lower subject contrast, and density buys back the contrast that photon energy took away.

Question 5. The density through the body of the designated hole IQI reads 2.4. What density range is acceptable across the area of interest, and what happens if a spot falls outside it? Answer: 2.04 to 3.12, which may be rounded to 2.0 and 3.1. The rule is minus 15% or plus 30% from the IQI-body density, and the result must also sit inside the 1.8 to 4.0 window. Where the variation is exceeded, an additional IQI is placed for each exceptional area and the radiograph is retaken. The area is not simply declared unreadable and set aside.

Question 6. How often is a densitometer calibrated, and to what tolerance? Answer: at least every 90 days during use, reading the density steps closest to 1.0, 2.0, 3.0 and 4.0 on a national standard step tablet or step wedge calibration film, and accepted where readings do not vary by more than 0.05 density units from the stated values. Verification checks run at the beginning of each shift, after eight hours of continuous use, or after a change of apertures, whichever comes first. Step wedge comparison films are verified annually to 0.1 density units.

Questions 7-9: Geometric unsharpness, source distance and latitude

Question 7. A 4 mm (0.160 in) source sits 10 in from the source-side surface of a 1.5 in thick weld, with the film against the far side. Is the geometry acceptable? Answer: no. Geometric unsharpness is source size multiplied by the source-side-to-detector distance, divided by the source-to-object distance: 0.160 times 1.5 divided by 10 gives 0.024 in. The limit for material under 2 in thick is 0.020 in. Move the source to 15 in and unsharpness falls to 0.016 in. The penumbra is a shadow-geometry problem, and it scales exactly the way a shadow on a wall does.

Question 8. State the geometric unsharpness limits by thickness. Answer: 0.020 in for material under 2 in, 0.030 in for 2 in through 3 in, 0.040 in for over 3 in through 4 in, and 0.070 in for material greater than 4 in. The limits loosen with thickness for a physical reason: inherent unsharpness from scatter generated inside thick material already dominates the image, so tightening the geometric term buys nothing. Holding a thin-section geometry over a 6 in wall would demand source distances that make exposure times unworkable.

Question 9. Moving the source from 10 in to 15 in fixed the unsharpness. What did it cost? Answer: 2.25 times the exposure. Intensity falls with the square of distance, so the exposure factor is 15 divided by 10, squared, which is 2.25. Every unsharpness problem solved by distance is paid for in time, and every unsharpness problem solved by a smaller focal spot is paid for in output. That trade is the whole of radiographic technique design, and it is why the technique sheet fixes source size, distance and exposure together rather than one at a time.

Questions 10-11: Source selection, half-value layer and shielding

Question 10. How much steel reduces an Iridium-192 beam to one thirty-second of its unshielded intensity? Answer: 62.5 mm. The half-value layer of Ir-192 in steel is approximately 12.5 mm, and one thirty-second is two to the power of minus five, so five half-value layers are required: five multiplied by 12.5 gives 62.5 mm. Attenuation is exponential rather than linear, which is why the second inch of shielding buys far less reduction than the first, and why barrier calculations are done in half-value layers instead of in millimetres.

Question 11. A 6 mm wall and a 75 mm wall both need radiographing. Which source for each? Answer: an X-ray tube or Ir-192 for the 6 mm wall, and Co-60 for the 75 mm wall. Ir-192 covers steel up to roughly 25 mm; Co-60 carries the energy for sections from about one inch to several inches. X-rays give the finest control on thin material because tube voltage can be lowered to raise subject contrast and focal spots are small. Higher photon energy penetrates further and flattens contrast at the same time, which is the trade you accept on heavy wall.

Questions 12-13: Backscatter and film processing artefacts

Question 12. A lead letter B appears light against a darker background on the developed film. Accept or reject? Answer: reject. A lead symbol B at least 1/2 in high and 1/16 in thick is attached to the back of each film holder for every exposure. A light image of the B on a darker background means radiation scattered from behind the film reached the emulsion, the B blocked it, and the surrounding area was fogged by that backscatter. A dark image of the B on a lighter background is not cause for rejection, because it shows the B was imaged by primary radiation as intended.

Question 13. Name the cause of each: a crescent-shaped dark mark, a branched jagged dark line, a circular pattern, and a straight streak. Answer: crimping from abrupt bending of the film, static discharge during rapid loading or unloading, water droplets drying on the film surface, and chemical carry-over or inadequate agitation during processing. The separating test is physical. View the film surface by reflected light: emulsion damage and residue show on the surface, while a discontinuity exists only in the transmitted image, correlates with weld geometry, and repeats in position on a retake.

Questions 14-15: Interpreting weld discontinuities

Question 14. Distinguish incomplete penetration from incomplete fusion on a radiograph. Answer: incomplete penetration images as a straight, sharply defined dark line of consistent width running along the weld centreline at the root, because the unfilled root gap is a uniform void bounded by two machined bevel faces. Incomplete fusion images as an elongated dark line offset from the centreline, following the fusion face, with one straight edge against the bevel and a more irregular edge against the weld metal. Position relative to the centreline is the discriminator, and width consistency confirms it.

Question 15. A weld radiograph shows a small bright spot against the darker weld image. What is it, and why is it bright? Answer: a tungsten inclusion from a GTAW electrode. Tungsten attenuates far more strongly than steel, so it passes less radiation to the film and leaves a light area — the opposite polarity to porosity and slag, which are less attenuating than steel and therefore image dark. Undercut images as a dark irregular band at the toe of the weld along the edge of the reinforcement, following the weld edge rather than sitting inside the deposit.

Cracks are the hardest call because visibility is governed by orientation. A crack is a tight planar discontinuity, so it images only when the beam runs close to its plane; a crack lying across the beam removes almost no material along the radiation path and produces no density change to see. That geometric blindness is the structural reason radiography is paired with an angled ultrasonic technique on critical welds, and the comparison is set out in RT versus UT for weld inspection.

The order of the checks, and why candidates reverse it

Every question above resolves into one sequence. First establish that the radiograph is a valid radiograph: sensitivity, density, density variation, geometric unsharpness, backscatter, identification and location markers. Only then interpret the image. A film that fails on density carries no reliable information about the weld, and rejecting a weld on the strength of an invalid film is as serious an error as accepting one.

The second habit is separating the technique failure from the weld failure in the report. Density 1.6 through the area of interest is a technique finding and the answer is a retake. Incomplete penetration, 35 mm long, at weld station 4 is a weld finding and the answer is a repair. Reports that blur the two produce arguments with clients that cost more than the radiography did, and our note on what makes an NDT report defensible works through the structure that keeps them apart.

The third is knowing which document governs which decision. Section V, Article 2 tells you how to make and qualify the radiograph. The construction code tells you what is acceptable in the weld, and the two are confused in the field constantly. Our breakdown of Section VIII Division 1 pressure vessel NDT covers the acceptance side. Density and IQI requirements are met against Article 2, not against the construction code that invoked it.

Where RT Level II sits, and what comes next

SNT-TC-1A recommends 40 hours of training, 210 hours of radiographic experience and 400 total NDT hours for RT Level I, then a further 40 hours of training, 630 hours of radiographic experience and 1,200 total NDT hours for RT Level II. Examination grading is a composite of at least 80% with no individual written examination below 70% and a practical grade of at least 80%. The method-by-method table is on our NDT training hours requirements page.

Radiography pays differently from ultrasonics in the US market because the radiation safety burden, the shift patterns and the licensing sit on top of the technical work. Industrial radiographers working with radioactive sources in the United States hold radiation safety credentials and work under a licence, which is separate from and additional to an SNT-TC-1A RT Level II certification. The current earnings picture is on the NDT Level II salary page.

Atlantis runs ASNT method training for radiographers and teams, built around your own equipment and written practice. Affordable, accessible, fully customizable. Where the weak point is the paperwork rather than the technician — procedures nobody has audited, film review that cannot be defended in front of a client — outsourced ASNT Level III consulting closes it faster than retraining does. Ask for a demo or a quote through contact.

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