radiographic testing in chennai
Radiographic Testing (RT), or industrial radiography, is a nondestructive testing (NDT) method of inspecting materials for hidden flaws by using the ability of shortwavelength electromagnetic radiation (high energy photons) to penetrate various materials.
Either an X-ray machine or a radioactive source, like Ir-192, Co-60, or in rarer cases Cs-137 are used in a X-ray computed tomography machine as a source of photons.Neutron radiographic testing (NR) is a variant of radiographic testing which uses neutrons instead of photons to penetrate materials. This can see very different things from X-rays, because neutrons can pass with ease through lead and steel but are stopped by plastics, water and oils.
Since the amount of radiation emerging from the opposite side of the material can be detected and measured, variations in this amount (or intensity) of radiation are used to determine thickness or composition of material. Penetrating radiations are those restricted to that part of the electromagnetic spectrum of wavelength less than about 10nanometres.
The beam of radiation must be directed to the middle of the section under examination and must be normal to the material surface at that point, except in special techniques where known defects are best revealed by a different alignment of the beam. The length of weld under examination for each exposure shall be such that the thickness of the material at the diagnostic extremities, measured in the direction of the incident beam, does not exceed the actual thickness at that point by more than 6%. The specimen to be inspected is placed between the source of radiation and the detecting device, usually the film in a light tight holder or cassette, and the radiation is allowed to penetrate the part for the required length of time to be adequately recorded.
The result is a two-dimensional projection of the part onto the film, producing a latent image of varying densities according to the amount of radiation reaching each area. It is known as a radio graph, as distinct from a photograph produced by light. Because film is cumulative in its response (the exposure increasing as it absorbs more radiation), relatively weak radiation can be detected by prolonging the exposure until the film can record an image that will be visible after development. The radiograph is examined as a negative, without printing as a positive as in photography. This is because, in printing, some of the detail is always lost and no useful purpose is served.
Before commencing a radiographic examination, it is always advisable to examine the component with one's own eyes, to eliminate any possible external defects. If the surface of a weld is too irregular, it may be desirable to grind it to obtain a smooth finish, but this is likely to be limited to those cases in which the surface irregularities (which will be visible on the radio graph) may make detecting internal defects difficult.
After this visual examination, the operator will have a clear idea of the possibilities of access to the two faces of the weld, which is important both for the setting up of the equipment and for the choice of the most appropriate technique.
Defects such as delaminations and planar cracks are difficult to detect using radiography, particularly to the untrained eye. Without overlooking the negatives of radiographic inspection, Radiography does hold many significant benefits over ultrasonics, particularly insomuch that as a 'picture' is produced, more accurate identification of the defect can be made, and by more interpreters. Very important as most construction standards permit some level of defect acceptance, depending on the type and size of the defect.
To the trained Radiographer, subtle variations in visible film density provide the technician the ability to not only accurately locate a defect, but identify its type, size and location; an interpretation that can be physically reviewed and confirmed by others, possibly eliminating the need for expensive and unnecessary repairs.
Either an X-ray machine or a radioactive source, like Ir-192, Co-60, or in rarer cases Cs-137 are used in a X-ray computed tomography machine as a source of photons.Neutron radiographic testing (NR) is a variant of radiographic testing which uses neutrons instead of photons to penetrate materials. This can see very different things from X-rays, because neutrons can pass with ease through lead and steel but are stopped by plastics, water and oils.
Since the amount of radiation emerging from the opposite side of the material can be detected and measured, variations in this amount (or intensity) of radiation are used to determine thickness or composition of material. Penetrating radiations are those restricted to that part of the electromagnetic spectrum of wavelength less than about 10nanometres.
The beam of radiation must be directed to the middle of the section under examination and must be normal to the material surface at that point, except in special techniques where known defects are best revealed by a different alignment of the beam. The length of weld under examination for each exposure shall be such that the thickness of the material at the diagnostic extremities, measured in the direction of the incident beam, does not exceed the actual thickness at that point by more than 6%. The specimen to be inspected is placed between the source of radiation and the detecting device, usually the film in a light tight holder or cassette, and the radiation is allowed to penetrate the part for the required length of time to be adequately recorded.
The result is a two-dimensional projection of the part onto the film, producing a latent image of varying densities according to the amount of radiation reaching each area. It is known as a radio graph, as distinct from a photograph produced by light. Because film is cumulative in its response (the exposure increasing as it absorbs more radiation), relatively weak radiation can be detected by prolonging the exposure until the film can record an image that will be visible after development. The radiograph is examined as a negative, without printing as a positive as in photography. This is because, in printing, some of the detail is always lost and no useful purpose is served.
Before commencing a radiographic examination, it is always advisable to examine the component with one's own eyes, to eliminate any possible external defects. If the surface of a weld is too irregular, it may be desirable to grind it to obtain a smooth finish, but this is likely to be limited to those cases in which the surface irregularities (which will be visible on the radio graph) may make detecting internal defects difficult.
After this visual examination, the operator will have a clear idea of the possibilities of access to the two faces of the weld, which is important both for the setting up of the equipment and for the choice of the most appropriate technique.
Defects such as delaminations and planar cracks are difficult to detect using radiography, particularly to the untrained eye. Without overlooking the negatives of radiographic inspection, Radiography does hold many significant benefits over ultrasonics, particularly insomuch that as a 'picture' is produced, more accurate identification of the defect can be made, and by more interpreters. Very important as most construction standards permit some level of defect acceptance, depending on the type and size of the defect.
To the trained Radiographer, subtle variations in visible film density provide the technician the ability to not only accurately locate a defect, but identify its type, size and location; an interpretation that can be physically reviewed and confirmed by others, possibly eliminating the need for expensive and unnecessary repairs.
Radiographic Testing - Benefits
- Can inspect assembled components
- Minimum surface preparation required
- Detects both surface and subsurface defects
- Provides a permanent record of the inspection
- Verify internal flaws on complex structures
- Isolate and inspect internal components
- Automatically detect and measure internal flaws
- Measure dimensions and angles within the sample
- without sectioning
- Sensitive to changes in thickness, corrosion, flaws and material density changes
Radiographic Testing - Application
Radiographic Testing is widely used in the;
- Aerospace industries
- Military defence
- Offshore industries
- Marine industries
- Power-gen industries
- Petrochem industries
- Waste Management
- Automotive industries
- Manufacturing industries
- Transport industries
- Non Destructive Testing
- Ndt Services
- Ultrasonic Testing
- Magnetic Particle Testing
- Dye Penetrant Testing
- Radiographic Testing
- Eddy Current Testing
- Vibration Analysis
- PAUT - TOFD
- Ultrasonic Thickness Gauging Testing
- Helium leak detection Services
- RFET / NFET / PECT Testing
- Internal Rotary Inspection system (IRIS)
- Acoustic Pulse Reflectometry (APR)
- Positive Material Identification Testing
- Magnetic flux leakage (MFL)
- Acoustic emission Testing
- Flouresent Leak Detection
- Long range ultrasonic testing - LRUT
- Thermography Inspection Services
- Leak Testing
- TKY Joints Ultrasonic Testing
- AWS D1.1 Structural steel ultrasonic Testing
- Ultrasonic Inspection
- Time of Flight Diffraction (TOFD) and Phased Array UT
- Magnetic Particle Testing
- Dye Penetrant Testing
- Radiographic Testing
- Eddy Current Testing
- Weld ability Study
- Visual Inspection and Field Services
- Ultrasonic Pulse Velocity Testing
- Rebound Hammer Testing
- Rebar Locator
- Depth of concrete
- Half Cell Potential Testing
- Carbonation Testing
- Pile Integrity Testing
- Visual Inspection and Field Services
- 1. Ultrasonic Pulse Velocity Testing
- 2. Rebound Hammer Testing
- 3. Rebar Locator
- 4. Depth of concrete
- 5. Half Cell Potential Testing
- 6. Carbonation Testing
- 7. Pile Integrity Testing
- 8. Visual Inspection and Field Services
- 9. In-Situ Compressive Strength (design strength, and existing structures)
- 1. Pile Testing Systems
- 2. Structural Monitoring Systems
- 3. Asphalt Testing Systems
- 4. Pavement Testing
- 5. Rock and Soil Laboratory Test Systems
- 6. Non-Destructive Tests for Concrete
- 7. Geotechnical & Vibration Monitoring Systems
- 8. Pavement Condition Monitoring
- 9. Concrete and Cement Lab Systems
- Laboratory Tests on Construction Materials as per Standards.
- 1. Cement
- 2. Aggregate
- 3. Bricks
- 4. Blocks
- 5. Tension test on rebars
- 6. Chemical test on Rebars
- 7. Water Analysis
- 8. Cube test
- 9. Accelerated cube test (ACT)
- 10. Rapid Chloride test (RCPT)
- 11. Concrete Mix Design
- 12. Fly ash
- 13. Slag and Silica fume
- 14. Self compacting concrete
- 15. Temperature controlled concrete
- 1. Civil NDT Investigation
- 2. Concrete Investigation
- 3. coating Thickness Measurement on Concrete Structures
- 4. Compressive Strength Testing
- 5. Concrete Mix Design
- 6. Bitumen Mix Design
- 7. Core extraction Testing
- 8. Core Sampling Testing
- 9. Concrete Core Testing
- 10. Concrete Cube Testing
- 11. Chemical Analysis
- 12. Electrical Resistivity Testing
- 13. Ground Penetrating Radar Survey
- 14. Sieve Analysis
- 15. Ultrasonic Low Frequency Testing
- 16. UPV Testing
- 17. Vibration Analysis of Building
- 18. Leak Testing
- 19. CT Scan on Conctete
- 20. Element Analysis on Concrete
- 21. Impact Echo Testing
- 22. Linear Polarization Testing
- 23. Load Testing
- 24. Permeability Testing
- 25. petrography of concrete
- 26. Pullout Testing
- 27. Cut and Pullout Testing (CPO Test)
- 28. Impulse Response Test
- 29. Impact Echo Test
- 30. Ground Penetrating Radar (GPR)
- 31. Crack Depth Measurement
- 1. Reinforcement Location by Ground Penetrating Radar (GPR)
- 2. Cover Assessment
- 3. Half Cell Potential Tests
- 4. Resistivity Tests
- 5. Corrosion Rate Assessment
- 6. Carbonation Test
- 1. Bond Test
- 2. Anchor / Rebar Pull-out Strength
- 3. Chemical Tests
NDT TESTING SERVICES (NON DESTRUCTIVE TESTING SERVICES)
NDT CAPABILITIES FOR MECHANICAL AND CIVIL
CIVIL NDT TESTING - NON-DESTRUCTIVE TESTING SERVICES
CIVIL NDT - CONCRETE TESTING SERVICES
CONSTRUCTION MATERIALS TESTING EQUIPMENTS:
LAB TESTING - CONCRETE AND CONCRETING MATERIALS
CIVIL NDT AND CONCRETE - TESTING SERVICES
Reinforcement Location and Corrosion Assessments
Repair Quality Assessment
list of ndt testing services in chennai
list of civil ndt testing services in chennai