Non Destructive Testing (NDT)
Non Destructive Testing (NDT) is a process of physical inspection of materials without causing any damage or harmful consequence to the material. It is widely used in Industry for checking quality of the production and also as part of routine inspection and maintenance in services. Therefore NDT is a tool to assure the quality of industrial components, assemblies and structures and that these are free from dangerous defects. Hence the obvious and clear benefits of using NDT is the identification of defects, which remain unchanged could result in a catastrophic failure which would be very costly and possibly loss of lives and machinery.
Five basic NDT methods are commonly used to examine materials. Those are Ultrasonic Testing (UT), Liquid Penetrant Testing (PT), Magnetic Particle Testing (MT), Eddy Current Testing (ET) and Radiographic Testing (RT). Among these NDT techniques, Radiographic and Ultrasonic Testing techniques are used for detection of internal defects. Magnetic, Penetrant and Eddy current Testing methods are commonly used for surface and just below surface defects. In addition, to these techniques there are some other NDT methods which have specific applications. These include Acoustic Emission, Leak Testing, Visual Testing, Strain Gauging, Thermography and Concrete Testing techniques. More advance NDT techniques which are coming to the industry are Digital Radiography, Phased Array Ultrasonic Testing and Computer Tomography.
Typical industries that benefit from NDT technology include Power Generation, Aerospace, Chemical, Heavy Mechanical Fabrication, Auto-mobiles, Oil and Gas, Ship Building, Foundries and Civil Engineering.
NDT technology can be used as an essential tool to improve the quality and reliability of these components, products, structures and to ensure the safety of both human and industry.
Well qualified NDT manpower and necessary NDT facilities are to be developed as per internally accepted levels through accredited NDT laboratories to use NDT technology effectively and efficiently.
In addition, qualified welders are very rare to be found in the country. Although there are many welder training institutes, there is no proper national programme to develop qualified welders in the country. X-ray qualified welders are highly essential human resource that are to be developed for the successes of the planned national projects in the forthcoming years in industrial sector, civil engineering and oil exploration and construction of off shore oil wells.
NDT in civil engineering specially for testing concrete structures for quality is also an essential technology that is to be developed in the country since many construction works have been planned to be initiated. Although there are many large scale constructions going on in civil engineering sector there is no properly planned programme to develop qualified manpower for testing such concrete structures. A programme for application of NDT in Civil Engineering (combing with certain Destructing Testing Techniques) is required to be initiated to use NDT technology more effectively in civil engineering sector.
On 18th November 2013, The Sri Lanka Accreditation Board for Conformity Assessment certified that the Certification Body for Non Destructive Testing (CBNDT) of Atomic Energy Authority which is located at No. 977/18, Bulugaha Junction, Kandy Road, Kelaniya, complies with the accreditation criteria for bodies operating certification of persons as described in ISO/ IEC 17024: 2003.
Further, this CBNDT has been accredited as a certification body under the field of Non Destructive Testing which has been assigned the accreditation number BP 001-01 with the scope of Qualification & Certification of Non Destructive Testing Personnel as per ISO 9712:2012
The Inspection Body of National Centre for Non Destructive Testing (NCNDT) is the Inspection Unit of NCNDT which mainly performs functional testing rather than analytical testing. In house inspections and field inspections in many industrial and construction sites cover majority of activities of the Non Destructive Testing (NDT). Generally, inspections involve direct determination of the integrity and conformity with specific requirements of items, products, structures and assemblies.
Operation of NDT inspection services is based on various international standards, codes and specifications, mainly ASTM/ASME and BS Standards, which are required by clients and their contract arrangements. Inspection Body of NCNDT primarily performs inspections in six main disciplines namely Radiographic Testing (RT), Ultrasonic Testing (UT), Magnetic Particle Testing (MT), Eddy Current Testing (ET), Liquid Penetrant Testing (PT) and Concrete Testing (CT).