Quantitative radiography

Conference · Fri Feb 01 00:00:00 EST 1991

OSTI ID:5645659

Logan, C M; Hernandez, J M; Devine, G J

We have developed a system of quantitative radiography in order to produce quantitative images displaying homogeneity of parts. The materials that we characterize are synthetic composites and may contain important subtle density variations not discernable by examining a raw film x-radiograph. In order to quantitatively interpret film radiographs, it is necessary to digitize, interpret, and display the images. Our integrated system of quantitative radiography displays accurate, high-resolution pseudocolor images in units of density. We characterize approximately 10,000 parts per year in hundreds of different configurations and compositions with this system. Images are captured using DuPont NDT55 industrial x-ray film in Daypack{trademark} packages. X-ray cabinets are of custom design, with helium flight path and a filter wheel for positioning filters if desired. The cabinets contain baffles to reduce scattered radiation and are equipped with drawer for rapid load/unload of parts. Separate units with tungsten-anode or copper-anode tubes are available. The usual operating voltage is 15 to 35 kVp. Fixturing provides for rough part positioning and precise alignment with respect to the x-ray source. Areal density standards are placed at several locations on each film. In interpreting the image, we use the standards nearest the image of the part being quantified. Because of this, small variations in x-ray flux uniformity (heel effects) are unimportant. The usual standard is a step wedge of aluminum containing 13 steps. Films are permanently labeled by imaging a perforated metal numbering strip. Data such as part number, step wedge identification, etc. are read from barcode labels and transferred to a data base for later retrieval and use in quantifying the image.

• Research Organization: Lawrence Livermore National Lab., CA (United States)
• Sponsoring Organization: USDOE; USDOE, Washington, DC (United States)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 5645659
• Report Number(s): UCRL-JC-105226; CONF-910399-8; ON: DE92011523
• Resource Relation: Conference: American Society for Nondestructive Testing spring conference, Oakland, CA (United States), 18-22 Mar 1991
• Country of Publication: United States
• Language: English

Related Subjects

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
X-RAY RADIOGRAPHY
EVALUATION
ALUMINIUM
DENSITY
DESIGN
DIGITIZERS
IMAGE PROCESSING
NUCLEAR EMULSIONS
SPATIAL RESOLUTION
ELECTRONIC CIRCUITS
ELEMENTS
INDUSTRIAL RADIOGRAPHY
METALS
PHYSICAL PROPERTIES
PROCESSING
PULSE CIRCUITS
RESOLUTION
SIGNAL CONDITIONERS
440101* - Radiation Instrumentation- General Detectors or Monitors & Radiometric Instruments