In Radiography Testing the test-part is placed between the radiation source and film (or detector). The material density and thickness differences of the test-part will attenuate (i.e. reduce) the penetrating radiation through interaction processes involving scattering and/or absorption. The differences in absorption are then recorded on film(s) or through an electronic means. In industrial radiography there are several imaging methods available, techniques to display the final image, i.e. Film Radiography, Real Time Radiography (RTR), Computed Tomography (CT), Digital Radiography (DR), and Computed Radiography (CR).
There are two different radioactive sources available for industrial use; X-ray and Gamma-ray. These radiation sources use higher energy level, i.e. shorter wavelength, versions of the electromagnetic waves. Because of the radioactivity involved in radiography testing, it is of paramount importance to ensure that the Local Rules is strictly adhered during operation.
Computed Tomography (CT) is one of the lab based advanced NDT methods that TWI offers to industry. CT is a radiographic based technique that provides both cross-sectional and 3D volume images of the object under inspection. These images allow the internal structure of the test object to be inspected without the inherent superimposition associated with 2D radiography. This feature allows detailed analysis of the internal structure of a wide range of components.
TWI Resources
TWI has the following digital radiography equipment with computed tomography capability to cater for industrial needs.
- Nikon 450kV micro-focus CT system
- X-Tek Industrial 450 kV broad focus system
- X-Tek 225kV micro-focus CT system
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
Applications
Radiographic Testing is widely used in the;
TWI also offers training in radiographic testing.
For more information about TWI's radiography testing services, please email contactus@twi.co.uk.