What Is Radiation:

What Is Radiation:

X and Gamma Rays are a family of waves that are called electromagnetic waves. X-rays and gamma rays differ only in their source of origin.  X-rays are produced by an x-ray generator and gamma radiation is the product of radioactive atoms.  They are both part of the electromagnetic spectrum. They are waveform, as are light rays, microwaves, and radio waves. X-rays and gamma rays cannot been seen, felt, or heard. They possess no charge and no mass and, therefore, are not influenced by electrical and magnetic fields and will generally travel in straight lines. However, they can be diffracted (bent) in a manner similar to light.

What is Radiation

What is Radiation :

X and Gamma Rays are a family of waves that are called electromagnetic waves. X-rays and gamma rays differ only in their source of origin.  X-rays are produced by an x-ray generator and gamma radiation is the product of radioactive atoms.  They are both part of the electromagnetic spectrum. They are wave forms, as are light rays, microwaves, and radio waves. X-rays and gamma rays cannot been seen, felt, or heard. They possess no charge and no mass and, therefore, are not influenced by electrical and magnetic fields and will generally travel in straight lines. However, they can be diffracted (bent) in a manner similar to light.

Surface contamination closes Discontinuity openings : Surface cleaning plays critical role for effective penetration testing

  • Any contamination such as oil, rust, scale, corrosion & different types of coatings and surface treatments cover the discontinuity opening and prevent entry of penetrant in to it.
  • To detect the discontinuities, test surface shall be free from above mentioned contamination, otherwise indications will not appear.

Introduction of the Magnetic Field

The required magnetic field can be introduced into a component in a number of different ways.

1.Using a permanent magnet or an electromagnet that contacts the test piece

2.Flowing an electrical current through the specimen

3.Flowing an electrical current through a coil of wire around the part or through a central conductor running near the part.

Detection of leakage field :

Detection of leakage field :
Finely divided iron particles are used for detection of leakage field. Leakage  field at the surface collects and hold the iron particles together to form visible indication patterns.

  • Flaws at or near the surface disturb the magnetic flux flow and produce leakage field at surface above the flaw.
  • Magnetic particle build up at the leakage field produces recognizable patterns which are interpreted.
  • Color of the particles must be chosen to provide adequate contrast against the part’s natural color.