18 Sep Radiography Testing In NDT – Course Details And Syllabus

What is Radiography Testing in NDT?

Radiography testing is also called Gamma ray or X-ray or RT which is a non-destructive testing method. In this testing, gamma-rays and X-rays are used to produce a radio-graph of the sample which in-turn examines the internal structure of the sample thereby identifying the flaws and defects if any. The production of X-rays and gamma-rays are from X-ray tubes and radioactive isotopes respectively. Even though this type of testing is a slow process as well as expensive, it’s one among the dependent ways to identify porosity, cracks, voids in weld interiors, inclusions,  etc. 

In this testing there is no need of compulsory surface preparation as in other types of ndt testing methods. RT is mainly used to make sure the material integrity of castings, welds, machine parts, piping, pressure vessels and many other objects. Also in the case of industrial installation inspection, this testing can be used. 

Principle behind the Technique

In radio graphic testing , the sample is placed between the radio graphic film and the radiation source. And then the radiation is passed through the sample from a certain distance. The weld or the sample will absorb the radiations passed through it and the amount varies depending on the places with and without the defects. 

The difference in the absorption of the material affects the amount of radiation received by the film which is happened through the particular plane of the sample. The radiation is detected and measured by the radio graphic film and then the film is processed. The resultant images are interpreted by the qualified inspectors and analyse the location as well as the type of defect found in the material. Most of the materials and the product forms like welds , composites, castings, etc can undergo radiography.

The main speciality of this testing is the picture or image of the highly sensitive internal structure of the sample which is a permanent record in the form of radio-graph. The absorption depends on the thickness and the density of the object. Places with cracks or porosity will appear as dark outlines whereas inclusions of low and high density places will appear as dark areas and light areas respectively.

Radio-graphics interpretation and the testing should be conducted only by qualified professionals because of the factors like threat behind the testing, high expenses due to false reading, etc

Benefits of Radiography Testing 

• Surface preparation is very less compared to other NDT testings
• Inspect and identify internal components
• Automatic detection and measurement of internal flaws
• Permanent record of inspection is obtained
• Can detect defects on the surface and the sub-surfaces
• Can inspect complex structures internal flaws also

Advantages and disadvantages of RT

Advantages 

• It is Volumetric since both surface and sub-surface inspections can be executed
• Less or no surface preparation is needed
• Material limitation is very less
• Permanent record is available
• Portability is very good especially for gamma sources
• Can detect significant variation in the composition
• Can detect hidden areas where direct access is not provided

Disadvantages 

• Radiation is hazardous
• Heavy and bulky equipment s are needed
• Expensive equipment’s are required
• Experienced and highly skilled person required for the exposure and the interpretation
• Process is relatively slow 
• Required two side access of the sample
• Not possible to detect depth of discontinuity

Enroll for 1 month preparatory classes for ASNT level 2 and 3 Radiography Testing Certification

Gamma NDT academy offers NDT preparatory classes for candidates who intend to appear for the ASNT Level 2 and 3 Radiography Testing certification exam and also provides certification in QC course in Kerala

We will cover all the syllabus under ASNT for Radiography testing and conduct mock tests to prepare you best for the certification exam. We will also share study materials and sample questions which you need to revise. We have a 100% success rate for NDT level 2 and 3 certification courses.

Gamma NDT academy training institute is located in Kerala, India. We provide online classes for candidates who cannot attend our training sessions in-person. Gamma NDT academy is well known for the NDT level 2 course and NDT level 3 course in India.