CRI IQI Selection & Radiographic Sensitivity 2

Question 1

What is the primary purpose of including an IQI in a radiographic setup?

Accepted Answer

To verify the radiographic technique provides adequate sensitivity to detect discontinuities

Answer

To directly measure the dimensions of discontinuities found in the weld

Answer

To calibrate the output of the X-ray generator or isotope source

Answer

To determine the optimum film density for the exposure

Question 2

Which type of IQI is most commonly specified in ASME Boiler and Pressure Vessel Code Section V for weld radiography?

Accepted Answer

Hole-type (plaque) IQI

Answer

Wire-type IQI

Answer

Step-wedge comparison IQI

Answer

Micro-dot IQI

Question 3

When multiple film placements are used to radiograph a circumferential weld, what is the minimum IQI requirement per placement?

Accepted Answer

One IQI per individual film placement

Answer

One IQI for the entire circumferential weld

Answer

Two IQIs per film placement, on opposite ends

Answer

One IQI for every three consecutive film placements

Question 4

When source-side IQI placement is impractical, and film-side placement is used instead, what must the radiographer do?

Accepted Answer

Place an 'F' designator on the IQI and document it in the radiographic report

Answer

Double the number of IQIs used to compensate for reduced sensitivity

Answer

Increase the radiation dose by 50% to account for the placement change

Answer

Switch from a hole-type to a wire-type IQI

Question 5

What is the 'essential hole' on a hole-type IQI?

Accepted Answer

The smallest-diameter hole that must be visibly discernible on the radiograph to satisfy code sensitivity requirements

Answer

The largest hole on the IQI used as a gross reference

Answer

The center mounting hole used to attach the IQI to the test object

Answer

A reference hole used exclusively for equipment calibration purposes

Question 6

How is radiographic sensitivity expressed as a percentage calculated using a hole-type IQI?

Accepted Answer

(IQI thickness ÷ specimen thickness) × 100

Answer

(Specimen thickness ÷ IQI thickness) × 100

Answer

(Visible hole diameter ÷ specimen thickness) × 100

Answer

(Source size ÷ source-to-film distance) × 100

Question 7

Which of the following factors does NOT directly determine the IQI designation number selected from code tables?

Accepted Answer

Source-to-film distance (SFD)

Answer

Nominal material thickness being radiographed

Answer

Whether a single-wall or double-wall technique is employed

Answer

The material type of the test object