Computed Radiography (CR)


Computed Radiography (CR) offers significant advantages by providing clients a digital radiograph that can be easily transferred. 

CR:

  • Uses equipment similar to conventional radiography
  • An imaging plate is placed under the object to be examined and exposed
  • The imaging plate is run through a special laser scanner to read and digitize the image.
  • The digital image can be viewed on a computer screen and can be enhanced using software that has functions very similar to other conventional digital image-processing software, such as contrast, brightness, filtration and zoom.

 

SubjectDetails
PrinciplesA phosphor coated imaging plate is placed under the object to be examined and a radiographic exposure is made. The imaging plate is processed by a laser scanner that digitizes the image. The image is fully erased from the plate after passing through the scanner. The digital image can be viewed and enhanced using digital imaging software.
How and where is it used?As an alternative to film radiography for internal examination, profiling, and characterization of a wide assortment of materials.

Non-code work
Applicable
Codes/Standards
Code work (ASME Section 5, Article II, Mandatory Appendix 8)
AWS D1.1 for filmless rad
API 1104 for filmless radiography
ASTM will allow
Form of report or deliverable?Permanent record radiograph in digital form that can be printed, saved, distributed
AdvantagesNo film storage nor chemical processes
Fast image acquisition
High sensitivity of imaging plate permits low strength exposure source
Safety areas can be considerably reduced
CR imaging can occur while other maintenance operations continue in production
Limitations
AlternativesRT, Digital Radiography (DR)

DR system almost instantly displays the image on a display in front of the radiographer, removing the need for processing; however, DR is difficult on piping over 3 in diameter difficult to inability to conform the rigid inspection plate to the pipe surface.
Certifications of technicians performing the work?
Rope access applicable?
Yes