CRI Equipment Calibration & Maintenance 2

Question 1

What is the primary purpose of a step wedge (penetrameter) in radiographic calibration?

Accepted Answer

To verify the density range and contrast sensitivity of the imaging system

Answer

A step wedge penetrameter verifies that the radiographic system can resolve the required density range and detect small thickness changes.

Question 2

How often should radiation output constancy checks typically be performed on a fixed industrial X-ray unit in active use?

Accepted Answer

Before each major inspection campaign or after servicing

Answer

Output constancy checks should be performed before each major inspection campaign and after any repair or servicing to ensure reproducible exposure conditions.

Question 3

Which parameter is directly adjusted when performing kV calibration on an X-ray generator?

Accepted Answer

Peak tube voltage accuracy

Answer

kV calibration verifies that the peak tube voltage output matches the set value, ensuring correct radiation energy for the intended application.

Question 4

A radiographer notices that images from a gamma-ray source appear consistently underexposed despite using standard exposure charts. The MOST likely equipment-related cause is:

Accepted Answer

Source activity decay beyond the exposure chart's reference date

Answer

Gamma sources continuously decay; if the exposure chart was created at a higher activity level, the source may no longer provide sufficient dose rate for the standard time.

Question 5

What does 'focal spot size' affect in radiographic image quality, and why is it periodically verified?

Accepted Answer

It affects geometric unsharpness; verified because it can increase with tube aging

Answer

The focal spot can enlarge as the tungsten anode erodes with use, increasing geometric unsharpness and reducing image definition.

(CRI) Certified Radiographic Interpreter Practice Test

(CRI) Certified Radiographic Interpreter Practice Test

CRI Equipment Calibration & Maintenance 2