GAMMA BASICS
What type of testing method is gamma radiography?
Non-destructive testing (NDT)
Name one radioactive isotope used in gamma radiography.
Cobalt-60 or Iridium-192
What is one major hazard of using gamma rays?
Radiation exposure
What does gauging measure?
Material thickness or dimensions
What do gamma rays create when they pass through an object?
An image showing internal structure or defects
What device captures the gamma rays after they pass through the object?
Film or digital detector
What must be used to protect personnel from gamma radiation?
Protective shielding and warning signs
What kind of waves are used in ultrasonic gauging?
High-frequency sound waves
What kind of defects can gamma radiography detect?
Cracks, voids, or inclusions
What’s used to hold and direct the radioactive source safely?
A gamma camera or exposure device
Why is gamma radiography considered portable?
It doesn’t require an external power source
Formula for ultrasonic thickness measurement?
(Sound velocity × travel time) ÷ 2
Why do thinner or defective areas appear darker on the image?
They allow more gamma rays to pass through to the detector
What type of gauging tool uses a calibrated screw to measure distance?
Mechanical gauge or micrometer
Name one advantage of gamma radiography over X-rays.
It’s more portable and can penetrate thicker materials
Name one key difference between mechanical and ultrasonic gauging.
Mechanical uses direct contact; ultrasonic uses sound waves and no contact