What kind of flaws will Radiography testing detect?

Objective of Radiography Testing is to detect internal flaws. Volumetric flaws such as voids, pinholes, slag, shrinkage are easily detected, whereas, planar defects such as laminations, laps and seams are difficult to defect. A defect should create notable amount of sectional difference to get detected. Flaws whose major plane is parallel to radiation beam been cannot be seen in Radiography.

What are the Advantages of Industrial Radiography?

• Permanent record.
• Can find Internal defect.
• Less material Limitations.
• Can easily see shape and size of defects.
• No need of power supply for Gamma ray.
• Gamma rays are portable.
• Non planner defect easily identify.

What are the limitation of Industrial Radiography testing?

• Health hazard due to radiation
• Initial cost, Labour and Consumable costs
• Skilled RT techncians required.
• Time consumption.
• Gamma ray is uncontrollable.
• Planner defect are difficult to identify.
• Dark room needed for film processing.
• Cannot measure depth of defect.
• Electricity needed for X-rays

How X-rays are produced for industrial RT testing?

• An x-ray machine maintains a potential difference between the filament and the tungsten target on applied KV is 200 KV.
• The target is usually of small dimension of around 2.3 mm.
• Copper rod is usually heated, thus coolant is essential.
• The target material should have high melting point.
• It should have high thermal conductivity.
• Tungsten having high atomic number 74 and melting point of 3400°C is the most preferred target material.
• When high speed electrons from Cathode are striking the target, partial energy will be converted to x-rays. These x-rays are emitted through the Beryllium window.

How Gammarays are produced in Industrial Radiography?

Let us understand about ‘Atom’.

• Atom is a smallest unit of material and it consist of three elements
• Proton
• Neutron
• Electron
• The Proton and Neutron are inside the Nucleus.
• The Electron revolves around the Nucleus.

Let us understand about ‘atomic number’

Number of protons or number of electron in an atom is called Atomic Number.

Then What is Atomoc Mass Number?

Number of Proton and Neutron in an Nucleus.

Therefore,  Number of Neutrons = Mass Number – Atomic Number

What is Isotope in RT? 

Elements having same atomic Number But Different Mass Number are called Isotopes.

Example for Isotopes :

HYDROGEN = ₁H¹ ,  ₁H² , ₁H³

URANIUM = ₉₂U²³⁵ , ₉₂U²³⁸

IRIDIUM = ₇₇Ir¹⁹¹,  ₇₇Ir¹⁹²

COBALT =   ₂₇Co⁵⁹, ₂₇Co⁶⁰    

Types of Isotopes :

1)Natural Isotopes:

 Atomic number above 82 elements can emit radiation automatically and such elements are called natural isotopes . Example: Uranium ₉₂U²³⁵ , Radium  ₈₂Ra²²⁶

2)Artificial Isotopes:

                    The isotopes produced in the atomic research centre.

          Example: Iridium  ₇₇Ir¹⁹², Cobalt  ₂₇CO⁶⁰, Selenium  ₃₄Se⁷⁴